JP5281607B2 - Laminate film - Google Patents

Description

  The present invention relates to a laminate film having excellent transparency, heat resistance, and impact resistance, and having a low thermal expansion.

  Conventionally, glass has been used by taking advantage of its characteristics such as transparency, heat resistance, low thermal expansion, and chemical stability, and has been widely used as optical glass for lenses, optical disks, display substrates, etc. for a long time. Have contributed. In recent years, in order to meet the demand for reducing the weight of members in such an industrial field, studies have been made to use a glass having a large specific gravity in a thin shape. However, since glass is vulnerable to impact and has the disadvantages of being easily broken, the reduction in yield due to cracking during the manufacturing process has become a problem in reducing the weight by reducing the thickness of the member. In order to improve the fragility, a thin film substrate having excellent flexibility and heat resistance has been proposed by laminating a resin layer mainly composed of a metal oxide polymer containing an organic group on the surface of a glass substrate (Patent Document). 1) However, these methods still use glass, and it is difficult to reduce the weight and improve the workability.

  By the way, in recent years, features such as weight reduction, thinning, and workability have been pushed to the front, and the movement of replacing glass with a transparent plastic material targeted for optical applications has attracted attention. Examples of the plastic material having excellent transparency include polymethyl methacrylate (PMMA), alicyclic polyolefin, epoxy resin, and silicone resin. Among them, PMMA and alicyclic polyolefin are called organic glass because they have particularly excellent transparency, and are frequently used for optical lenses, light guide plates for liquid crystal displays, and optical disks. However, since these materials have a low heat distortion temperature, it is difficult to use them in the production of a display element substrate with a heat process of 150 ° C. to 200 ° C. or more, for example, and the use as a glass substitute is limited. .

  In the past, the present inventors have proposed an invention relating to a plastic film using a cage silsesquioxane resin having high transparency and heat resistance and excellent dimensional stability in Patent Document 2. However, although this plastic film has a sufficient impact strength in the case of a thick film, there is room for improvement because a thin film may cause minute scratches depending on the handling during manufacture, which may lead to a decrease in yield. was there.

Japanese Patent Laid-Open No. 2004-50565 JP 2006-89685 JP

  The present invention provides a laminate film that is excellent in transparency, heat resistance, and impact resistance and has low thermal expansion.

  As a result of intensive investigations in view of the problems of the prior art as described above, the present inventors are excellent in terms of heat resistance, transparency, and low thermal expansion, but on the other hand, further improvement in impact resistance is achieved. By laminating a layer with excellent heat resistance, transparency, and impact resistance (outer layer) on one or both sides of the required layer (inner layer), the outer layer's impact absorbing layer can be used to make the inner layer more susceptible to cracking. By making up for it, it is possible to improve the ease of cracking, and by suppressing high thermal expansion in the in-plane direction of the outer layer with the inner layer, a laminated film having heat resistance, transparency, impact resistance, and low thermal expansion can be obtained. As a result, the present invention has been completed.

（但し、ｍは１〜３の整数であり、Ｒ₁は水素原子又はメチル基を示す）のいずれか一つから選ばれる有機官能基であり、ｎ＝8、10、12又は14である〕で表される籠型シルセスキオキサン樹脂を含有した硬化性樹脂組成物からなる第一の層に、下記一般式（５）
Ｙ−[Ｚ−(Ｏ_1/2−Ｒ² ₂ＳｉＯ_1/2)_a−(Ｒ³ＳｉＯ_3/2)_k−(Ｏ_1/2)_b]_l−Ｚ−Ｙ
(５)
〔但し、Ｒ²及びＲ³はビニル基、アルキル基、フェニル基、（メタ）アクリロイル基、アリル基又はオキシラン環を有する基であって、Ｒ²又はＲ³において、各置換基は互いに同じか異なるものであってもよいが、１分子中に含まれるＲ³のうち少なくとも１つはビニル基、（メタ）アクリロイル基、アリル基又はオキシラン環を有する基のいずれかである。また、a及びbは0〜3の数であって、1≦a+b≦4の関係を満たし、kは8〜14の数を示し、kが奇数の場合は、aとbはゼロを含めた偶数と奇数との組み合わせであり、kが偶数の場合は、aとbはゼロを含めた偶数の組み合わせであり、lは1〜2000の数を示す。更に、Ｚは下記一般式（６）

（但し、Ｒ⁴は水素原子、ビニル基、アルキル基、フェニル基、(メタ)アクリロイル基、アリル基又はオキシラン環を有する基であって、Ｒ⁴は互いに同じか異なるものであってもよく、また、ｐは0〜30の数を示す。）で表される２価の基であり、Ｙは下記一般式（７）〜（１０）から選ばれるいずれかの１価の基である。
[(Ｒ⁵Ｏ)Ｒ⁶ ₂ＳｉＯ_1/2]_c−[Ｒ⁷ＳｉＯ_3/2]_d−[Ｏ_1/2]− （７）
[Ｒ⁵Ｏ_1/2]_e−[Ｒ⁷ＳｉＯ_3/2]_d−[Ｏ_1/2−Ｒ⁶ ₂ＳｉＯ_1/2]− （８）
(Ｒ⁵Ｏ_1/2)− （９）
(Ｒ⁵ ₃ＳｉＯ_1/2)− （１０）
（但し、Ｒ⁶及びＲ⁷はビニル基、アルキル基、フェニル基、(メタ)アクリロイル基、アリル基、又はオキシラン環を有する基であって、Ｒ⁶又はＲ⁷において、各置換基は互いに同じか異なるものであってもよく、Ｒ⁵は水素原子、メチル基又はエチル基から選ばれ、また、ｃ及びeは0〜3の数であり、dは8〜14の数であり、ｄが奇数の場合は、ｃとeはそれぞれ独立に０又は２であり、ｄが偶数の場合は、ｃとeはそれぞれ独立に１又は３である。）〕で表される構成単位を有する籠型シルセスキオキサン含有硬化性シリコーン共重合体を含有した硬化性樹脂組成物からなる第二の層が積層してなることを特徴とする積層体フィルムである。 That is, the present invention provides the following general formula (1)
[RSiO _3/2 ] _n (1)
[However, R is the following general formula (2), (3) or (4)

(Wherein m is an integer of 1 to 3 and R ₁ represents a hydrogen atom or a methyl group), and n = 8, 10, 12 or 14] In the first layer comprising a curable resin composition containing a cage silsesquioxane resin represented by the following general formula (5)
^{_{Y- [Z- (O 1/2 -R 2}} 2 SiO 1/2) a - (R 3 SiO 3/2) k - (O 1/2) b] l -Z-Y
(5)
[However, R ² and R ³ are vinyl group, alkyl group, phenyl group, (meth) acryloyl group, allyl group or group having an oxirane ring, and in R ² or R ³ , are each substituents the same as each other? Although they may be different, at least one of R ³ contained in one molecule is any of a vinyl group, a (meth) acryloyl group, an allyl group, or a group having an oxirane ring. Further, a and b are numbers from 0 to 3, satisfying the relationship of 1 ≦ a + b ≦ 4, k is a number from 8 to 14, and when k is an odd number, a and b are zero. When k is an even number, a and b are even number combinations including zero, and l represents a number from 1 to 2000. Furthermore, Z is the following general formula (6)

(However, R ⁴ is a hydrogen atom, vinyl group, alkyl group, phenyl group, (meth) acryloyl group, allyl group or a group having an oxirane ring, and R ⁴ may be the same or different from each other, P is a divalent group represented by 0 to 30), and Y is any monovalent group selected from the following general formulas (7) to (10).
[(R ⁵ O) R ⁶ ₂ SiO _1/2 ] _c- [R ⁷ SiO _3/2 ] _d- [O _1/2 ]-(7)
[R ⁵ O _1/2 ] _e- [R ⁷ SiO _3/2 ] _d- [O _1/2 -R ⁶ ₂ SiO _1/2 ]-(8)
(R ⁵ O _1/2 ) − (9)
(R ⁵ ₃ SiO _1/2 ) − (10)
(However, R ⁶ and R ⁷ are vinyl groups, alkyl groups, phenyl groups, (meth) acryloyl groups, allyl groups, or groups having an oxirane ring, and in R ⁶ or R ⁷ , each substituent is the same as each other. R ⁵ is selected from a hydrogen atom, a methyl group or an ethyl group, c and e are a number from 0 to 3, d is a number from 8 to 14, and d is In the case of an odd number, c and e are each independently 0 or 2, and in the case where d is an even number, c and e are each independently 1 or 3.)] A laminated film comprising a second layer made of a curable resin composition containing a silsesquioxane-containing curable silicone copolymer.

  According to the laminate film of the present invention, a cocoon-type silsesquioxane-containing curable silicone copolymer is formed on one or both sides of the first layer comprising a curable resin composition containing a cocoon-type silsesquioxane resin. Is a laminate film formed by laminating a second layer made of a curable resin composition containing, so that a laminate film having excellent transparency, heat resistance and impact resistance and low thermal expansion is obtained. be able to. Such laminated films are, for example, liquid crystal display element substrates, color filter substrates, organic EL display element substrates, electronic paper substrates, TFT substrates, solar cell substrates, and other transparent substrates, touch panels, and transparent electrodes. As an optical film application such as attached film, light guide plate, protective film, polarizing film, retardation film, lens sheet, etc., as a glass substitute material for various transport machinery, housing window materials, etc., its application range has become widespread and its industrial use It is extremely valuable.

  Hereinafter, the laminate film of the present invention will be described in detail based on preferred embodiments.

（但し、ｍは１〜３の整数であり、Ｒ₁ は水素原子又はメチル基を示す）のいずれか一つから選ばれる有機官能基であり、n=8、10、12又は14である〕で表される籠型シルセスキオキサン樹脂を含有した硬化性樹脂組成物からなる層を用いる。 In the present invention, the first layer (also referred to as the inner layer) of the laminate film has the following general formula (1).
[RSiO _3/2 ] _n (1)
[However, R is the following general formula (2), (3) or (4)

(Wherein m is an integer of 1 to 3 and R ₁ represents a hydrogen atom or a methyl group), and n = 8, 10, 12 or 14] The layer which consists of a curable resin composition containing the cage silsesquioxane resin represented by these is used.

  The vertical silsesquioxane resin used for forming the first layer has a molecular weight distribution and a molecule having a reactive functional group composed of an organic functional group having a (meth) acryloyl group, a glycidyl group or a vinyl group in all silicon atoms. It is preferably a cage-type silsesquioxane resin having a controlled structure, but it may be partially substituted with an alkyl group, a phenyl group or the like, and is not a completely closed polyhedral structure, but a part thereof. It may be a structure like a cleavage. Moreover, the average molecular weight of such cage-type silsesquioxane resin is not particularly limited, and such cage-type silsesquioxane resin may be an oligomer.

  The curable resin composition containing the vertical silsesquioxane resin used for forming the first layer is compatible with and reactive with the vertical silsesquioxane resin in addition to the vertical silsesquioxane resin. It is good that it is a curable resin composition in which a curable resin having the above is mixed. The curable resin composition containing such a cage silsesquioxane resin is a resin composition that can be cured by heat treatment, or a resin composition that can be cured by irradiation with active energy rays.

  Examples of the curable resin having compatibility and reactivity with the cage silsesquioxane resin include, for example, a reactive oligomer or a low molecular weight, low viscosity reaction which is a polymer having about 2 to 20 repeating structural units. Ionic monomer. Specifically, reactive oligomers include epoxy acrylate, epoxidized oil acrylate, urethane acrylate, unsaturated polyester, polyester acrylate, polyether acrylate, vinyl acrylate, polyene / thiol, silicone acrylate, polybutadiene, and polystyrylethyl methacrylate. Etc. can be illustrated. As reactive monomers, styrene, vinyl acetate, N-vinylpyrrolidone, butyl acrylate, 2-ethylhexyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, n-decyl acrylate, isobornyl acrylate, dicyclopentenyloxyethyl acrylate Monofunctional monomers such as phenoxyethyl acrylate and trifluoroethyl methacrylate, or dicyclopentanyl diacrylate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, bisphenol A diglycidyl ether diacrylate, tetraethylene glycol diacrylate Acrylate, hydroxypivalate neopentyl glycol diacrylate, trimethylolpropane triacrylate, penta Risuri tall triacrylate, pentaerythritol tetraacrylate, can be exemplified polyfunctional monomers such as dipentaerythritol hexaacrylate.

  As the curable resin having compatibility and reactivity with the cage silsesquioxane resin, in addition to those exemplified above, various reactive oligomers and monomers can be used. Two or more types may be mixed and used.

  Various additives can be added to the curable resin composition containing the cage silsesquioxane resin used for forming the first layer without departing from the object of the present invention. Various additives include organic / inorganic fillers, plasticizers, flame retardants, heat stabilizers, antioxidants, light stabilizers, UV absorbers, lubricants, antistatic agents, mold release agents, foaming agents, nucleating agents, colorants, Examples thereof include, but are not limited to, a crosslinking agent and a dispersion aid.

  The curable resin composition containing the saddle type silsesquioxane resin used for forming the first layer needs to contain the saddle type silsesquioxane resin. The content of the silsesquioxane resin is preferably 3% by mass or more, and more preferably 5 to 50% by mass. When the content is less than the lower limit, the obtained laminate film lacks heat resistance, which is important in the manufacturing process of a display element substrate accompanied by a thermal process. On the other hand, when the content exceeds the above upper limit, the toughness of the resulting film is impaired, and defects such as cracks on the surface and breakage of the film are likely to occur due to handling.

  The curable resin composition containing the cage silsesquioxane resin used for forming the first layer may further contain a polymerization initiator, if necessary. Such a polymerization initiator may be a photopolymerization initiator or a thermal polymerization initiator, and commercially available ones can be appropriately selected and used. Examples of the photopolymerization initiator include alkynephenone, acylphosphine oxide, and titanocene. Examples of the thermal polymerization initiator include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, and peroxyesters.

  In the present invention, an appropriate solvent can be used as a diluent to adjust the viscosity of the curable resin composition, etc., but taking into account the solvent devolatilization step requires time and reduces production efficiency. In the curable resin composition to be applied, it is preferable to keep the content of the solvent at 5% or less because a residual solvent or the like is present inside the resin layer obtained later and leads to deterioration of the properties of the molded film. More preferably, it is preferable to use one that does not contain a solvent. Moreover, it is preferable that such curable resin composition is a thing which does not generate | occur | produce a volatile matter in the case of hardening.

（但し、Ｒ⁴は水素原子、ビニル基、アルキル基、フェニル基、(メタ)アクリロイル基、アリル基又はオキシラン環を有する基であって、Ｒ⁴は互いに同じか異なるものであってもよく、また、ｐは0〜30の数を示す。）で表される２価の基であり、Ｙは下記一般式（７）〜（１０）から選ばれるいずれかの１価の基である。
[(Ｒ⁵Ｏ)Ｒ⁶ ₂ＳｉＯ_1/2]_c−[Ｒ⁷ＳｉＯ_3/2]_d−[Ｏ_1/2]− （７）
[Ｒ⁵Ｏ_1/2]_e−[Ｒ⁷ＳｉＯ_3/2]_d−[Ｏ_1/2−Ｒ⁶ ₂ＳｉＯ_1/2]− （８）
(Ｒ⁵Ｏ_1/2)− （９）
(Ｒ⁵ ₃ＳｉＯ_1/2)− （１０）
（但し、Ｒ⁶及びＲ⁷はビニル基、アルキル基、フェニル基、(メタ)アクリロイル基、アリル基、又はオキシラン環を有する基であって、Ｒ⁶又はＲ⁷において、各置換基は互いに同じか異なるものであってもよく、Ｒ⁵は水素原子、メチル基又はエチル基から選ばれ、また、ｃ及びeは0〜3の数であり、dは8〜14の数であり、ｄが奇数の場合は、ｃとeはそれぞれ独立に０又は２であり、ｄが偶数の場合は、ｃとeはそれぞれ独立に１又は３である。）｝で表される構成単位を有する籠型シルセスキオキサン含有硬化性シリコーン共重合体を含有した硬化性樹脂組成物からなる層を用いる。 In the present invention, the second layer (also referred to as the outer layer) of the laminate film has the following general formula (5).
^{_{Y- [Z- (O 1/2 -R 2}} 2 SiO 1/2) a - (R 3 SiO 3/2) k - (O 1/2) b] l -Z-Y
(5)
[However, R ² and R ³ are vinyl group, alkyl group, phenyl group, (meth) acryloyl group, allyl group or group having an oxirane ring, and in R ² or R ³ , are each substituents the same as each other? Although they may be different, at least one of R ³ contained in one molecule is any of a vinyl group, a (meth) acryloyl group, an allyl group, or a group having an oxirane ring. Further, a and b are numbers from 0 to 3, satisfying the relationship of 1 ≦ a + b ≦ 4, k is a number from 8 to 14, and when k is an odd number, a and b are zero. When k is an even number, a and b are even number combinations including zero, and l represents a number from 1 to 2000. Furthermore, Z is the following general formula (6)

(However, R ⁴ is a hydrogen atom, vinyl group, alkyl group, phenyl group, (meth) acryloyl group, allyl group or a group having an oxirane ring, and R ⁴ may be the same or different from each other, P is a divalent group represented by 0 to 30), and Y is any monovalent group selected from the following general formulas (7) to (10).
[(R ⁵ O) R ⁶ ₂ SiO _1/2 ] _c- [R ⁷ SiO _3/2 ] _d- [O _1/2 ]-(7)
[R ⁵ O _1/2 ] _e- [R ⁷ SiO _3/2 ] _d- [O _1/2 -R ⁶ ₂ SiO _1/2 ]-(8)
(R ⁵ O _1/2 ) − (9)
(R ⁵ ₃ SiO _1/2 ) − (10)
(However, R ⁶ and R ⁷ are vinyl groups, alkyl groups, phenyl groups, (meth) acryloyl groups, allyl groups, or groups having an oxirane ring, and in R ⁶ or R ⁷ , each substituent is the same as each other. R ⁵ is selected from a hydrogen atom, a methyl group or an ethyl group, c and e are a number from 0 to 3, d is a number from 8 to 14, and d is In the case of an odd number, c and e are each independently 0 or 2, and in the case where d is an even number, c and e are each independently 1 or 3.)} A layer made of a curable resin composition containing a silsesquioxane-containing curable silicone copolymer is used.

  The cage silsesquioxane-containing curable silicone copolymer used for forming the second layer is preferably a cage silsesquioxane-containing curable silicone copolymer having a controlled molecular weight distribution and molecular structure. However, the molecular weight distribution may be wide, and there is no particular limitation as long as the weight average molecular weight is 7000 or more.

  The curable resin composition used for forming the second layer is a cocoon-type silsesquioxane-containing curable silicone copolymer, and compatibility and reactivity with the cocoon-type silsesquioxane-containing curable silicone copolymer. It is good that it is a curable resin composition in which a curable resin having the above is mixed.

  Examples of the curable resin having compatibility and reactivity with the cage-type silsesquioxane-containing curable silicone copolymer include, for example, a reactive oligomer that is a polymer having about 2 to 20 repeating structural units, or a low Examples thereof include reactive monomers having a low molecular weight and low molecular weight. Specifically, reactive oligomers include epoxy acrylate, epoxidized oil acrylate, urethane acrylate, unsaturated polyester, polyester acrylate, polyether acrylate, vinyl acrylate, polyene / thiol, silicone acrylate, polybutadiene, and polystyrylethyl methacrylate. Etc. can be illustrated. As reactive monomers, styrene, vinyl acetate, N-vinylpyrrolidone, butyl acrylate, 2-ethylhexyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, n-decyl acrylate, isobornyl acrylate, dicyclopentenyloxyethyl acrylate Monofunctional monomers such as phenoxyethyl acrylate and trifluoroethyl methacrylate, or dicyclopentanyl diacrylate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, bisphenol A diglycidyl ether diacrylate, tetraethylene glycol diacrylate Acrylate, hydroxypivalate neopentyl glycol diacrylate, trimethylolpropane triacrylate, penta Risuri tall triacrylate, pentaerythritol tetraacrylate, can be exemplified a multifunctional monomer such as dipentaerythritol hexaacrylate, be used each of which alone or may be used in combination of two or more.

  Various additives can be added to the curable resin composition used for forming the second layer without departing from the object of the present invention. Various additives include thermoplastic resins and thermosetting elastomers and rubbers, organic / inorganic fillers, plasticizers, flame retardants, thermal stabilizers, antioxidants, light stabilizers, UV absorbers, lubricants, antistatic agents, release agents. Examples of the molding agent, foaming agent, nucleating agent, coloring agent, cross-linking agent, and dispersion aid may be mentioned, but the invention is not limited thereto.

  The content of the cocoon-type silsesquioxane-containing curable silicone copolymer in the curable resin composition used for forming the second layer is preferably 3% by weight or more. When the content is less than the lower limit, the heat resistance, which is important in the manufacturing process of the display element substrate accompanied by the thermal process, is insufficient.

  The curable resin composition used for forming the second layer may further have a polymerization initiator, if necessary. Such a polymerization initiator may be a photopolymerization initiator or a thermal polymerization initiator, and commercially available ones can be appropriately selected and used. Examples of the photopolymerization initiator include alkynephenone, acylphosphine oxide, and titanocene. Examples of the thermal polymerization initiator include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, and peroxyesters.

  In the present invention, an appropriate solvent can be used as a diluent to adjust the viscosity of the curable resin composition, etc., but taking into account the solvent devolatilization step requires time and decreases the production efficiency. Since the residual solvent or the like is present inside the resulting resin layer and leads to deterioration of the properties of the molded film, the content of the solvent in the curable resin composition to be applied is preferably 5% or less, More preferably, one containing no solvent is used. Moreover, it is preferable that such curable resin composition is a thing which does not generate | occur | produce a volatile matter in the case of hardening.

  The laminate film of the present invention is preferably a laminate film having a three-layer structure of “second layer (outer layer) —first layer (inner layer) —second layer (outer layer)”. Compared with a laminate film having a two-layer structure in which a resin layer serving as an outer layer is provided only on one side, warping, deformation, and the like of the film can be reduced. Further, the two curable resin compositions of the outer layers may be formed from the same component, and the curable resin compositions on each surface may be different within a range in which deformation such as warpage and deflection does not increase. .

  The thickness ratio of the outer layer to the inner layer (outer layer thickness / inner layer thickness) of the laminate film is preferably 0.01 or more and 1.0 or less, more preferably 0.025 or more and 1.0 or less. If the thickness ratio is less than the lower limit, the outer layer becomes too thin, and the effect as the shock absorbing layer, which is a feature of the outer layer, is not sufficiently exhibited, and the laminate film may be easily damaged. On the other hand, when the thickness ratio exceeds the upper limit, the outer layer becomes too thick, and the thermal expansion in the in-plane direction of the surface layer cannot be restricted by the inner layer, and the dimensional stability of the laminate film may be deteriorated. Furthermore, the amount of deflection of the laminate film is increased, and the impact resistance of the inner layer cannot be improved.

  Regarding the thickness of the laminate film, it is necessary that the thickness ratio of the inner layer and the outer layer satisfy the above-mentioned range, but it is more preferable that the total thickness of the laminate film is 10 to 1000 μm, more preferably 50. It is good to be -200 micrometers. When the thickness of the laminate film is less than the lower limit, the thickness of the laminate film becomes too thin, and the rigidity as the laminate film is insufficient. In addition, when the thickness of the laminate film exceeds the upper limit, the inner layer film alone has sufficient impact resistance as a film, and thus the intention of producing a laminate structure is reduced.

  As for the transparency of the laminate film, for example, the light transmittance at a wavelength of 550 nm of the laminate film before heating is preferably 85% or more, particularly preferably 90% or more. Furthermore, the light transmittance at a wavelength of 550 nm after heat treatment at 150 ° C. for 2 hours is preferably 85% or more, particularly preferably 90% or more. In the present invention, the transparency as described above can be ensured by laminating the second layer showing the light transmittance in the above range on the first layer showing the light transmittance in the above range.

  Regarding the thermal expansion coefficient of the laminate film of the present invention, since the thermal expansion in the in-plane direction of the outer layer is constrained by the inner layer excellent in low thermal expansion, the single layer has the same thermal expansion behavior in the in-plane direction and the thickness direction. Even if it is shown, by making a laminate film, a part of the thermal expansion of the outer layer appears as an increase in the thermal expansion in the thickness direction, and the thermal expansion coefficient of the laminate film is a value different in the plane direction and the thickness direction Will be shown. Therefore, the coefficient of thermal expansion of the laminate film of the present invention referred to below is the coefficient of thermal expansion in the in-plane direction in the state of the laminate film.

  The linear expansion coefficient in the in-plane direction of the laminate film is preferably 80 ppm / K or less, more preferably 60 ppm / K or less. When the linear expansion coefficient exceeds the upper limit, when used as a material for a display substrate, a touch panel or the like, the difference in the linear expansion coefficient with the peripheral members becomes large in a manufacturing process including a thermal process, resulting in insufficient reliability. Moreover, as for the linear expansion coefficient of each layer constituting the laminate film, it is preferable to use a layer whose linear expansion coefficient of the inner layer is less than 80 ppm / K and whose linear expansion coefficient of the outer layer is 80 ppm / K or more. When the linear expansion coefficient of the inner layer is 80 ppm / K or more, the linear expansion coefficient of the laminate film is increased, and the intention of producing a laminated structure as a laminate film excellent in low thermal expansion is reduced. If the coefficient of linear expansion of the outer layer is 80 ppm / K or less, the film has a sufficiently low thermal expansion property as a single layer, so that the intention of producing a laminated structure is reduced. In the first place, the thermal expansion in the in-plane direction of the laminate film can suppress the linear expansion coefficient to the value of the inner layer as the laminate film by constraining the expansion of the outer layer, so the upper limit of the linear expansion coefficient of the outer layer The value is not specified.

  Regarding the elastic modulus of the laminated film, the elastic modulus of the outer layer needs to be smaller than the elastic modulus of the inner layer. When the elastic modulus of the outer layer is larger than the elastic modulus of the inner layer, the amount of deflection of the laminate film becomes large and impact resistance cannot be improved. Further, the linear expansion coefficient of the outer layer becomes dominant, and the thermal expansion coefficient in the in-plane direction of the outer layer may not be suppressed.

  The production method of the laminate film of the present invention is not particularly limited. For example, a liquid saddle mold serving as an outer layer is formed on both sides of a film obtained by curing a curable resin composition containing a saddle silsesquioxane resin serving as an inner layer. Examples include a method of producing a laminate film by applying a curable resin composition containing a silsesquioxane-containing curable silicone copolymer, and a vertical silsesquioxane-containing curable silicone copolymer as an outer layer. A method of producing a laminate film by sandwiching a curable resin composition containing a liquid cage silsesquioxane resin as an inner layer with a film obtained by curing a curable resin composition containing a polymer is also included. Furthermore, a method of applying a liquid curable resin composition as an outer layer and an inner layer and simultaneously curing, or a film obtained by curing a curable resin composition containing a cage silsesquioxane resin as an inner layer, and an outer layer And a film obtained by thermocompression bonding with a film obtained by curing a curable resin composition containing a cage silsesquioxane-containing curable silicone copolymer. Each layer is preferably excellent in adhesion, but in order to further improve the adhesion of each layer, for example, the surface of the film may be subjected to surface activation treatment such as corona discharge treatment, ultraviolet irradiation treatment, plasma treatment, etc. Good.

  Hereinafter, although the laminated body film of this invention and its preparation method are demonstrated in detail by an Example and a comparative example, this invention is not limited to the following Example.

[Synthesis Example 1: Production of curable resin used to form first layer (inner layer)]
The cage silsesquioxane resin used for forming the inner layer material was synthesized as follows by the method described in JP-A-2004-143449.
A reaction vessel equipped with a stirrer, a dropping funnel, and a thermometer was charged with 40 ml of 2-propanol (IPA) as a solvent and 3.1 g of a 5% tetramethylammonium hydroxide aqueous solution (TMAH aqueous solution) as a basic catalyst. . To the dropping funnel, 15 ml of IPA and 12.7 g of 3-methacryloxypropyltrimethoxysilane were added, and an IPA solution of 3-methacryloxypropyltrimethoxysilane was added dropwise at room temperature over 30 minutes while stirring the reaction vessel. After completion of dropwise addition of 3-methacryloxypropyltrimethoxysilane, the mixture was gradually returned to room temperature and stirred for 2 hours without heating. After stirring, IPA was removed under reduced pressure and dissolved in 50 ml of toluene.

[Synthesis Example 2: Production of curable resin used to form second layer (outer layer material)]
A cage-type silsesquioxane-containing curable silicone copolymer resin used for forming the outer layer material was synthesized by the method described in JP-A-2009-227863 as follows.
The reaction vessel was charged with 250 ml of toluene and 52.5 g of phenyltrichlorosilane and cooled to 0 ° C. An appropriate amount of water was added dropwise and stirred until hydrolysis was complete. After the hydrolysis product was washed with water, 8.3 ml of a commercially available 30% benzyltrimethylammonium hydroxide solution was added, and the mixture was heated to reflux temperature for 4 hours. The whole was then cooled and left for about 96 hours. The slurry obtained after the elapse of time was heated again to the reflux temperature for 24 hours, then cooled and filtered to obtain 37.5 g of octaphenylsilsesquioxane as a white powder.

  Next, 100 ml of toluene, 0.123 g of tetramethylammonium hydroxide (1.35 mmol, 0.49 g as a 25% methanol solution), 20.3 g of the above octaphenylsilsesquioxane ( 19.7 mmol) and 5.12 g (19.7 mmol) of 3-methacryloxypropyldiethoxymethylsilane were added, heated at 80 ° C. for 1 hour to distill off methanol, further heated to 100 ° C., and returned to room temperature after 2 hours. The reaction was terminated. In the reaction solution, it was judged that the white powder of octaphenylsilsesquioxane disappeared and the reaction was completely progressed.

  The reaction solution was neutralized with 10% aqueous citric acid solution, washed with water, and dehydrated with anhydrous magnesium sulfate. The anhydrous magnesium sulfate was filtered off and concentrated to obtain 19.7 g of a colorless and transparent viscous liquid in a yield of 78%. The structure of the obtained cage silsesquioxane was confirmed by GPC and NMR measurement. Furthermore, under a nitrogen atmosphere, in a reaction vessel equipped with a dropping funnel and a condenser tube, 15 ml of toluene, 9.0 g (7 mmol) of the above obtained silsesquioxane, and 4 mg (0.044 mmol, tetramethylammonium hydroxide) 153 mg) as a 2.5% methanol solution. While stirring the reaction solution at 70 ° C., 4.6 g of silanol-terminated polydimethylsiloxane (DMS-S12: Mn (number average molecular weight) = 400-700: Asmax Corporation) was added dropwise from a dropping funnel over 3 hours. The mixture was further stirred for 3 hours and then cooled to room temperature.

  The reaction solution was neutralized with 10% aqueous citric acid solution, washed with water, and dehydrated with anhydrous magnesium sulfate. The anhydrous magnesium sulfate was filtered off and concentrated to obtain 12.5 g of a cocoon-type silsesquioxane-containing curable silicone copolymer as a colorless and transparent viscous liquid. As a result of measuring GPC of the obtained cocoon-shaped silsesquioxane-containing curable silicone copolymer, the weight average molecular weight (Mw) was 14000. Moreover, as a result of measuring 1H-NMR, it confirmed that it was resin which mainly used the cage silsesquioxane containing curable silicone copolymer.

[Example 1]
Cage-type silsesquioxane-containing curable silicone copolymer obtained in Synthesis Example 2: 30 parts by weight, dicyclopentanyl diacrylate: 70 parts by weight, and 2-hydroxy-2-methylpropio as a photopolymerization initiator Phenone: A liquid curable resin composition obtained by mixing 1.5 parts by weight and degassing was obtained. Next, the curable resin composition was cast on a glass plate using a roll coater so as to have a thickness of 15 μm, and the glass plate was further covered from above, and a high pressure mercury lamp of 80 W / cm was used, and 2000 mJ / After being cured with an accumulated exposure amount of cm ² , the cured film was peeled off from the glass to obtain two outer layer fills having a predetermined thickness.

Next, the cage silsesquioxane resin obtained in Synthesis Example 1: 20 parts by weight, trimethylolpropane triacrylate: 25 parts by weight, dicyclopentanyl diacrylate: 55 parts by weight, and 1- Hydroxycyclohexyl phenyl ketone: Mixing 2.5 parts by weight and defoaming the liquid curable resin composition to a thickness of 50 μm using the roll coater on the one outer layer film obtained above And then pressure-bonded with another film for the outer layer from above, and cured using an 80 W / cm high-pressure mercury lamp with an accumulated exposure of 2000 mJ / cm ² [outer layer material (thickness: 15 μm) A laminate film having a three-layer structure of —inner layer material (thickness: 50 μm) —outer layer material (thickness: 15 μm) ”was obtained.

[Example 2]
A laminate having a three-layer structure of outer layer (thickness: 15 μm) -inner layer (thickness: 80 μm) -outer layer (thickness: 15 μm)] except that the cast thickness of the inner layer was changed to 80 μm. A body film was obtained.

[Example 3]
The outer layer (thickness: 25 μm) -inner layer (thickness: 50 μm) -outer layer (thickness: 25 μm)] has a three-layer structure in the same manner as in Example 1 except that the thickness of the outer layer film is changed to 25 μm. A laminate film was obtained.

[Example 4]
Vertical silsesquioxane resin obtained in Synthesis Example 1: 20 parts by weight, trimethylolpropane triacrylate: 25 parts by weight, dicyclopentanyl diacrylate: 55 parts by weight, and 1-hydroxycyclohexylphenyl as a photopolymerization initiator Ketone: 2.5 parts by weight were mixed and defoamed to obtain a liquid curable resin composition. Next, the curable resin composition was cast on a glass plate using a roll coater so as to have a thickness of 50 μm, and the glass plate was further covered from above, and an 80 W / cm high-pressure mercury lamp was used. After curing with an accumulated exposure amount of cm ² , the cured film was peeled off from the glass to obtain an inner layer film having a predetermined thickness.

Next, the cage-type silsesquioxane-containing curable silicone copolymer obtained in Synthesis Example 2: 30 parts by weight, dicyclopentanyl diacrylate: 70 parts by weight, and 2-hydroxy-2-2 as a photopolymerization initiator Methylpropiophenone: A liquid curable resin composition obtained by mixing 1.5 parts by weight and degassing was obtained. Next, the curable resin composition is cast on a glass plate using a roll coater so as to have a thickness of 15 μm, and the inner layer film is covered from above, and the curable resin composition is further applied to the roll coater. The film was cast to a thickness of 15 um, covered with glass, cured with an integrated exposure of 2000 mJ / cm ² using an 80 W / cm high-pressure mercury lamp, and then cured from glass. Was peeled off to obtain a laminate film having a three-layer structure of [outer layer (thickness: 15 μm) −inner layer (thickness: 50 μm) −outer layer (thickness: 15 μm)].

[Example 5]
Cage-type silsesquioxane-containing curable silicone copolymer obtained in Synthesis Example 2: 50 parts by weight, dicyclopentanyl diacrylate: 50 parts by weight, and 2-hydroxy-2-methylpropio as a photopolymerization initiator Phenone: A liquid curable resin composition obtained by mixing 1.5 parts by weight and degassing was obtained. Next, the curable resin composition was cast on a glass plate using a roll coater so as to have a thickness of 15 μm, and the glass plate was further covered from above, and a high pressure mercury lamp of 80 W / cm was used, and 2000 mJ / After being cured with an integrated exposure amount of cm ² , the cured film was peeled off from the glass to obtain two outer layer films having a predetermined thickness.

Next, the cage silsesquioxane resin obtained in Synthesis Example 1: 20 parts by weight, trimethylolpropane triacrylate: 25 parts by weight, dicyclopentanyl diacrylate: 55 parts by weight, and 1- Hydroxycyclohexyl phenyl ketone: Mixing 2.5 parts by weight and defoaming the liquid curable resin composition to a thickness of 50 μm using the roll coater on the one outer layer film obtained above And then pressure-bonded with another film for the outer layer from above, and cured using an 80 W / cm high-pressure mercury lamp with an accumulated exposure amount of 2000 mJ / cm ² [outer layer (thickness: 15 μm) A laminate film having a three-layer structure of —inner layer (thickness: 50 μm) —outer layer (thickness: 15 μm) ”was obtained.

[Comparative Example 1]
Vertical silsesquioxane resin obtained in Synthesis Example 1: 25 parts by weight, trimethylolpropane triacrylate: 20 parts by weight, dicyclopentanyl diacrylate: 55 parts by weight, and 1-hydroxycyclohexylphenyl as a photopolymerization initiator Ketone: 2.5 parts by weight were mixed and defoamed to obtain a liquid curable resin composition. Next, using a roll coater on a glass plate, cast to a thickness of 80 μm, and further cover the glass plate from above, using an 80 W / cm high-pressure mercury lamp with an integrated exposure amount of 2000 mJ / cm ^2. After being cured, the cured film was peeled off from the glass to obtain a single layer film having a predetermined thickness.

[Comparative Example 2]
Cage-type silsesquioxane-containing curable silicone copolymer obtained in Synthesis Example 2: 30 parts by weight, dicyclopentanyl diacrylate: 70 parts by weight, and 2-hydroxy-2-methylpropio as a photopolymerization initiator Phenone: 1.5 parts by weight was mixed and defoamed to obtain a liquid curable resin composition. Next, using a roll coater on a glass plate, cast to a thickness of 80 μm, and further cover the glass plate from above, using an 80 W / cm high-pressure mercury lamp with an integrated exposure amount of 2000 mJ / cm ^2. After being cured, the cured film was peeled off from the glass to obtain a single layer film having a predetermined thickness.

[Comparative Example 3]
Cage-type silsesquioxane-containing curable silicone copolymer obtained in Synthesis Example 2: 50 parts by weight, dicyclopentanyl diacrylate: 50 parts by weight, and 2-hydroxy-2-methylpropio as a photopolymerization initiator Phenone: 1.5 parts by weight was mixed and defoamed to obtain a liquid curable resin composition. Next, using a roll coater on a glass plate, cast to a thickness of 80 μm, and further cover the glass plate from above, using an 80 W / cm high-pressure mercury lamp with an integrated exposure amount of 2000 mJ / cm ^2. After being cured, the cured film was peeled off from the glass to obtain a single layer film having a predetermined thickness.

[Comparative Example 4]
A PMMA (MR-200, manufactured by Mitsubishi Rayon Co.) sheet having a thickness of 0.6 mm was prepared.

  About the film of the Example and comparative example prepared above, the following physical-property evaluation was performed. The results are shown in Table 1.

[Evaluation method: Light transmittance]
Using a UV-visible spectrophotometer (U4000 manufactured by Hitachi, Ltd.), the light transmittance spectrum at 400 to 800 nm is measured for each film before heating and after heating at 150 ° C. for 2 hours, The transmittance of light with a wavelength of 550 nm is shown as a representative value.

[Evaluation method: Glass transition temperature]
In the dynamic mechanical analysis (DMA) apparatus, the temperature at which tan δ was maximized under the conditions of a heating rate of 5 ° C./min, a distance between chucks of 10 mm, and 16 Hz was defined as the glass transition temperature.

[Evaluation method: Linear expansion coefficient]
In the tensile load mode of the thermomechanical analyzer (TMA), the change in the amount of thermal expansion from 50 ° C. to 150 ° C. was measured at a temperature rising rate of 5 ° C./min. In Comparative Example 4, since the amount of linear expansion was abrupt at 100 ° C. or higher, the change in the amount of thermal expansion from 50 ° to 90 ° C. was measured.

[Evaluation method: Tensile modulus]
The tensile modulus of each film at 25 ° C. was measured using a tensile tester (ORITEEC RTE-1210). At this time, the measurement was performed under the conditions of a distance between chucks of 50 mm and a tensile speed of 2 mm / min.

[Evaluation method: Drop weight impact test]
A test of free-falling a 40 g weight (R = 2.5 mm) from an arbitrary height perpendicularly to the surface of the outer film of the laminate film is conducted 5 times or more, and this laminate film is destroyed with a probability of 50% or more. When the height was evaluated.

  The physical properties of the films obtained in Examples and Comparative Examples are as shown in Table 1. In Examples 1 to 5 and Comparative Example 1, no clear glass transition temperature was observed at 300 ° C. or lower. From the above results, in the examples, a film having both heat resistance, impact resistance and low thermal expansion was obtained, whereas in Comparative Example 1, although it had heat resistance, compared to the laminate film of the example It was confirmed that the film had insufficient impact resistance. In Comparative Examples 2 and 3, only a film having high impact resistance but insufficient low thermal expansion could be obtained. Further, in Comparative Example 4, the film was deformed by heating at 150 ° C. in the heat resistance test, and the linear expansion coefficient increased in a high temperature region of 100 ° C. or higher, resulting in a sheet having insufficient heat resistance.

Claims (1)

The following general formula (1)
[RSiO _3/2 ] _n (1)
[However, R is the following general formula (2), (3) or (4)

(Wherein m is an integer of 1 to 3 and R ₁ represents a hydrogen atom or a methyl group), and n = 8, 10, 12 or 14] In the first layer comprising a curable resin composition containing a cage silsesquioxane resin represented by the following general formula (5)
^{_{Y- [Z- (O 1/2 -R 2}} 2 SiO 1/2) a - (R 3 SiO 3/2) k - (O 1/2) b] l -Z-Y
(5)
[However, R ² and R ³ are vinyl group, alkyl group, phenyl group, (meth) acryloyl group, allyl group or group having an oxirane ring, and in R ² or R ³ , are each substituents the same as each other? Although they may be different, at least one of R ³ contained in one molecule is any of a vinyl group, a (meth) acryloyl group, an allyl group, or a group having an oxirane ring. Further, a and b are numbers from 0 to 3, satisfying the relationship of 1 ≦ a + b ≦ 4, k is a number from 8 to 14, and when k is an odd number, a and b are zero. When k is an even number, a and b are even number combinations including zero, and l represents a number from 1 to 2000. Furthermore, Z is the following general formula (6)

(However, R ⁴ is a hydrogen atom, vinyl group, alkyl group, phenyl group, (meth) acryloyl group, allyl group or a group having an oxirane ring, and R ⁴ may be the same or different from each other, P is a divalent group represented by 0 to 30), and Y is any monovalent group selected from the following general formulas (7) to (10).
[(R ⁵ O) R ⁶ ₂ SiO _1/2 ] _c- [R ⁷ SiO _3/2 ] _d- [O _1/2 ]-(7)
[R ⁵ O _1/2 ] _e- [R ⁷ SiO _3/2 ] _d- [O _1/2 -R ⁶ ₂ SiO _1/2 ]-(8)
(R ⁵ O _1/2 ) − (9)
(R ⁵ ₃ SiO _1/2 ) − (10)
(However, R ⁶ and R ⁷ are vinyl groups, alkyl groups, phenyl groups, (meth) acryloyl groups, allyl groups, or groups having an oxirane ring, and in R ⁶ or R ⁷ , each substituent is the same as each other. R ⁵ is selected from a hydrogen atom, a methyl group or an ethyl group, c and e are a number from 0 to 3, d is a number from 8 to 14, and d is In the case of an odd number, c and e are each independently 0 or 2, and in the case where d is an even number, c and e are each independently 1 or 3.)] A laminate film comprising a second layer made of a curable resin composition containing a silsesquioxane-containing curable silicone copolymer.