JPH11105209A - Mold release film for thermo-setting resin laminated plate, and manufacture of thermo-setting resin laminated plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide excellent joining property and mold release property between a supporting body and a coating layer without spoiling characteristics of the supporting body by a method wherein at least on one surface of the film-form supporting body, the coating layer including a fluorine-containing resin, and a resin which has a sea island-form micro phase separation structure with the fluorine-containing resin, is coated. SOLUTION: At least on one surface of a film-form supporting body, a coating layer including a fluorine-containing resin, and a resin (binder resin) which has a sea island-form micro phase separation structure with the fluorine-containing resin, is coated. As a representative film supporting body, there are polyethylene terephthalate, etc., being a polyester resin film, and as the fluorine-containing resin, there are a monopolymer or a copolymer of a fluorine-containing vinyl polymerizable monomer, etc., and from a viewpoint of the adhering property to the film-form supporting body, a resin comprising a copolymer containing a polymerizing unit of (meth)acrylate having a fluorine-containing alcohol residue is preferable, and as the binder resin, a melamine resin and a urethane resin are desirable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a release film for a thermosetting resin laminate used when press-forming a thermosetting resin laminate, and a thermosetting resin laminate using the release film. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Generally, a release film composed mainly of a fluorine-containing resin is used under conditions where heat resistance of 190 ° C. or more is required, and a film composed of a synthetic resin, such as polypropylene or polyethylene, is used at lower temperatures. And a film obtained by coating a silicone resin or silicone oil on the surface of a film made of these synthetic resins.

[0003] Release films coated with a fluorine-containing resin are disclosed in JP-A-61-228078 and JP-A-58-21.
491, JP-A-1-154740, JP-A-4-2907
46, and those described in JP-A-4-246532 are known, but all of them are aimed at releasing from an adhesive and are different from the uses in the present invention.

[0004] Thermosetting resin laminates are widely used as electrical insulating materials. Further, the surface of the laminated board is provided with properties other than insulating properties and the like, that is, a carbon resistance ink is applied, a wiring circuit is formed via an adhesive, and the like, and used as a flexible printed board or a multilayer printed wiring board. Have been. In particular, glass epoxy laminates are widely used as thermosetting resin laminates.

[0005] Thermoset resin laminates are manufactured by using a prepreg made by impregnating a thermosetting resin with a woven or nonwoven fabric of cellulosic fiber, glass fiber, or the like, between two press hot plates. The required number of sheets are stacked and molded at high temperature and pressure.

At this time, a release film is used for release between the press hot plate and the laminated product, and the prepreg is primarily crosslinked via the release film, and then a plurality of prepregs are secondary crosslinked. The method of bonding and manufacturing a multilayer laminate is common.

[0007] The release film of the present invention can be suitably used for producing a thermosetting resin laminate including an interstitial via hole (hereinafter referred to as IVH). IVH is a through hole that penetrates between two or more layers of conductors of a multilayer printed wiring board and does not penetrate the entire thermosetting resin laminate.

[0008] In the IVH, there is a blind via hole in which the existence of a through-hole can be seen from the surface of the wiring board, and the existence of the through-hole cannot be recognized from the surface of the thermosetting resin laminate because it completely enters the thermosetting resin laminate. There are two types of buried via holes. In each case, a through hole is plated after a hole is formed in the laminate, and the laminate is laminated with a copper foil or another laminate using an adhesive prepreg.

[0009]

However, a release film in which a silicone resin is coated on a film made of a synthetic resin has good releasability from a prepreg, but has a problem that a silicone component is transferred to a laminate product. Was.

[0010] These problems can be reduced by using a release film made of a fluorine-containing resin, but the fluorine-containing resin is expensive and is uneconomical for applications that do not require high temperatures. There is also a method of coating a film made of a synthetic resin with a fluorine-containing resin, but the film-forming property of the fluorine-containing resin is generally insufficient, so that a film having a uniform thickness cannot be obtained and the release property is insufficient. Also, there is a problem that the adhesive force between the film containing the fluorine-containing resin and the synthetic resin is weak, and the resin component is transferred to the laminate product.

[0011]

Means for Solving the Problems The present inventors apply a coating layer having a sea-island-like microphase-separated structure on a film-like support to obtain a film-forming property, a releasability, and a non-transfer property. And found that the present invention was completed.

[0012] The present invention provides a thermosetting resin laminate in which a coating layer containing a fluorine-containing resin and a resin forming a sea-island-like microphase-separated structure with the fluorine-containing resin is applied on at least one surface of a film-like support. Provided are a release film for use and a method for producing a thermosetting resin laminate using the release film.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The material of the film-like support of the present invention is not particularly limited, and various known plastic films can be used as the support. Typical examples are polyester resin film, polycarbonate resin film, triacetyl cellulose resin film, cellophane, polyamide resin film, polyphenylene sulfide resin film, polyetherimide resin film, polyether sulfone resin film, polysulfone resin film, polyolefin resin film, etc. Is mentioned. Mechanical properties,
A polyester resin film and a polyphenylene sulfide resin film are preferred from the viewpoint of thermal characteristics and price, and a polyester resin film is particularly preferred.

The polyester resin film is a general term for a polymer film containing a carboxylic acid ester group in the main chain.
Preferred polyesters include poly (ethylene terephthalate), poly (ethylene 2,6-naphthalate),
Examples thereof include poly (ethylene α, β-bis- (2-chlorophenoxy) ethane-4,4′-dicarboxylate) and polybutylene terephthalate. Considering quality, economy and the like, polyethylene terephthalate is particularly preferred.

The thickness of the film-shaped support is not particularly limited, and may be 0.5 to 0.5 depending on the stiffness required for the release film.
An appropriate thickness can be set from the range of 500 μm. Also,
The surface roughness, haze, etc. of the film-like support are not particularly limited, and the thickness of the coating layer and the adhesive strength required between the coating layer and the film-like support in the present invention are required as a release film. It can be appropriately set in consideration of the transparency and the like.

The release film of the present invention is a coating comprising a fluorine-containing resin and a resin forming a sea-island-like microphase-separated structure with the fluorine-containing resin on at least one surface of the film-like support (hereinafter also referred to as a binder resin). Layers are applied.

Typical examples of the fluorine-containing resin include a homopolymer or copolymer of a fluorine-containing vinyl polymerizable monomer, a fluorine-containing vinyl polymerizable monomer and a vinyl polymerizable monomer not containing a fluorine atom. And a mixture thereof with a body, or a mixture thereof.

In the following, acrylate and methacrylate are collectively referred to as (meth) acrylate. Examples of the fluorine-containing resin include a polymer containing a polymerized unit of (meth) acrylate having a fluorine-containing alcohol residue, poly [perfluoropentyl vinyl ether], poly [α,
β, β-trifluorostyrene], polyvinylidene fluoride, polyhexafluoropropylene, porotetrafluoroethylene, and the like. As the fluorine-containing resin of the present invention, a resin made of a polymer containing a polymerized unit of (meth) acrylate having a fluorine-containing alcohol residue is preferable from the viewpoint of adhesiveness to a film-like support.

(Meth) having a fluorinated alcohol residue
Acrylate refers to a fluorinated alcohol ester of (meth) acrylic acid.
This refers to the remaining group obtained by removing the hydroxyl group from the fluorinated alcohol.

(Meth) having a fluorinated alcohol residue
As the acrylate, a (meth) acrylate containing a polyfluoroalkyl group (hereinafter, a polyfluoroalkyl group is referred to as an ^Rf group) in a fluorine-containing alcohol residue portion (hereinafter, referred to as an ^Rf group-containing (meth) acrylate). Is preferred.

As the ^Rf group-containing (meth) acrylate, a (meth) acrylate represented by the following formula 1 or 2 is preferable. However, A represents a divalent organic group, and R
^f shows a C1-C20 polyfluoroalkyl group. CH ₂ ＣＨCH-COO-A-R ^f Formula 1 CH ₂ ＣC (CH ₃ ) -COO-A-R ^f Formula 2

[0022] ^the R ^f group in ^the R ^f group-containing (meth) acrylate means two or more of the hydrogen atoms of the alkyl group substituted by fluorine atoms. The carbon number of the R ^f group is 1 to
20 is preferable, and especially 4-16 is preferable. Also, R ^f
The structure of the group may be linear or branched.
The proportion of fluorine atoms in the R ^f groups, [(R ^f number of fluorine atoms in the group) / (number of hydrogen atoms contained in the alkyl group of the same number of carbon atoms corresponding to ^the R ^f group)] × 100 (%) When represented by the formula, it is preferably 60% or more, more preferably 80% or more, and particularly preferably substantially 100%.

The R ^f group may contain a chlorine atom,
An etheric oxygen atom or a thioetheric sulfur atom may be inserted between carbon-carbon bonds.
The terminal carbon atom of the R ^f group bonded to A has
Preferably, one or more fluorine atoms are bonded. R
^A hydrogen atom or a chlorine atom may be present at the terminal portion of the ^f group. Also, all of the hydrogen atoms of the alkyl group (hereinafter referred to as R ^F group.) Perfluoroalkyl group substituted with fluorine atoms and is preferably.

The R ^F group is represented by C _n F _{2n + 1-} (where n is 4
Shows an integer of ~ 16. ) Is preferable, and a group in which n is 6 to 12 is particularly preferable. Specific examples of the ^RF group are shown below, but are not limited thereto.

[0025] _{C 4 F 9 - [CF 3} (CF 2) 3 -, (C
_{F 3) 2 CFCF 2 -,} (CF 3) 3 C-, and CF
₃ CF ₂ (CF ₃ ) CF— and the like.
C ₅ F ₁₁ - [example _{CF 3 (CF 2) 4 -} ], C 6 F
_13- [for example, CF ₃ (CF ₂ ) _5- ], C ₇ F _15-
[For example _{CF 3 (CF 2) 6 -} ], C 8 F 17 - [ example _{CF 3 (CF 2) 7 -} ], C 9 F 19 - [ such as C
F ₃ (CF ₂ ) ₈ −], C ₁₀ F ₂₁ − [for example, CF ₃
(CF ₂ ) ₉ −], CHF ₂ (CF ₂ ) _m − (where,
m is an integer of 1 to 15).

A represents-(CH ₂ ) _p -,-(CH
(CH ₃ ) CH ₂ ) _q -,-(CH ₂ ) _p N (C _x H
_{2x + 1) CO -, -} (CH 2) p N (C x H 2x + 1) SO 2
-And the like. Here, p, q and x each represent an integer of 1 or more, p is preferably 2, q is preferably 1, and x
Is preferably 1 to 3.

As the ^Rf group-containing (meth) acrylate, the following specific examples are given. However, in the formula, R ¹ represents a hydrogen atom or a methyl group, and R ^f represents a polyfluoroalkyl group.

[0028]

Embedded image CH ₂ ＣC (R ¹ ) COOCH ₂ CH ₂ R ^f CH ₂ ＣC (R ¹ ) COOCH (CH ₃ ) CH ₂ R ^f CH ₂ ＣC (R ¹ ) COOCH ₂ CH ₂ N (CH ₃ ) C
OR ^f CH ₂ ＣC (R ¹ ) COOCH ₂ CH ₂ N (CH ₃ ) S
^{_{O 2 R f CH 2 = C}} (R 1) COOCH 2 CH 2 N (C 2 H 5)
COR ^f CH ₂ ＣC (R ¹ ) COOCH ₂ CH ₂ N (C ₂ H ₅ )
SO ₂ R ^f CH ₂ ＣC (R ¹ ) COOCH ₂ CH ₂ N (C ₃ H ₇ )
COR ^f CH ₂ ＣC (R ¹ ) COOCH ₂ CH ₂ N (C ₃ H ₇ )
SO ₂ R ^f

The polymer containing polymerized units of ^the R ^f group-containing (meth) acrylate may comprise a one polymerized units of ^the R ^f group-containing (meth) acrylate, two or more polymerization units May be included. The term “polymerized unit” in the present invention refers to the minimum unit among the repeating units when a compound having a polymerizable group such as a vinyl group is polymerized. When two or more polymerized units of the ^Rf group-containing (meth) acrylate are included, two ^Rf groups having different carbon numbers may be used.
It is preferable to use at least one ^Rf group-containing (meth) acrylate.

Examples of the vinyl polymerizable monomer containing no fluorine atom include hydrocarbon vinyl polymerizable monomers and functional group-containing vinyl polymerizable monomers. Specific examples include vinyl chloride, behenyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, ethylene, vinyl acetate, styrene, α-methylstyrene, p-methylstyrene, (meth) acrylic acid and the like. Alkyl ester, hydroxyalkyl (meth)
Acrylate, polyoxyalkylene (meth) acrylate, (meth) acrylamide, diacetone (meth) acrylamide, methylolated (meth) acrylamide,
N-methylol (meth) acrylamide, vinyl alkyl ether, halogenated alkyl vinyl ether, vinyl alkyl ketone, butadiene, isoprene, chloroprene, glycidyl (meth) acrylate, aziridinyl (meth) acrylate, benzyl (meth) acrylate, isocyanateethyl (meth) Examples thereof include acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, maleic anhydride, (meth) acrylate having polysiloxane, and N-vinylcarbazole.

Among the vinyl polymerizable monomers containing no fluorine atom, hydrocarbon vinyl polymerizable monomers having a long-chain alkyl group such as a behenyl group, a stearyl group, a lauryl group, etc. are excellent in releasability. Are particularly preferred.

As the binder resin in the present invention, those capable of forming a sea-island-like microphase-separated structure with a fluorine-containing resin are preferable. When a microphase separation structure is formed, a coating layer having excellent film forming properties, adhesion to a film-like support, and strength of the coating layer can be obtained. Specific examples include a melamine resin and a urethane resin, and a urethane resin is particularly preferable.

A preferred urethane resin is a polyfunctional isocyanate and a compound having two or more groups that react with an isocyanate group (hereinafter also referred to as an isocyanate-reactive compound).
And the reaction product of

As the polyfunctional isocyanate, a polyisocyanate having two or more isocyanate groups and a modified product thereof are preferable, and examples thereof include an aliphatic polyfunctional isocyanate, an alicyclic polyfunctional isocyanate, and an aromatic polyfunctional isocyanate. As the modified form, a modified form of a nullate, a modified form of trimethylol, or a modified form of a buret is preferable. In the polyfunctional isocyanate, a part of the isocyanate group may be blocked.

Specific examples of the polyfunctional isocyanate include:
Hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI), tolylene diisocyanate (T
DI), phenylene diisocyanate (PDI), diphenylmethane diisocyanate (MDI), hydrogenated M
DI and the like, and isocyanurate modified products, trimethylol modified products thereof, trisburet or trifunctional amine derivatives, and the like.

The group which reacts with the isocyanate group in the isocyanate-reactive compound is preferably a hydroxyl group, an amino group, a carboxyl group or the like, and particularly preferably a hydroxyl group. As the compound having two or more groups that react with the isocyanate group, a polyether-based, polyester-based, or polycarbonate-based polyol having two hydroxyl groups is preferable.

There are hydrophilic and hydrophobic urethane resins. When a hydrophilic urethane resin is taken as an example, a non-reactive hydrophilic urethane resin is represented by the following formula:
Obtained by reacting a diol with a diisocyanate.

[0038]

Embedded image n [HO (C ₂ H ₄ O) _m H] + (n−1)
[OCNRNCO] → HO [(C ₂ H ₄ O) _m CONH
RNHCOO] _n-1 (C ₂ H ₄ O) _m H

Wherein R is an alkylene group having 6 to 25 carbon atoms (including a cycloalkylene group), m is an integer of 1 to 20, and n is an integer of 2 to 500.

The reactive hydrophilic urethane resin is prepared by synthesizing a isocyanate prepolymer at both ends from a polyol or a diol having a carboxyl group in the molecule and a diisocyanate, and then adding sodium bisulfite (NaHSO).
It is obtained by reacting with a blocking agent such as ₃ ).

The fluorine-containing resin and the binder resin are preferably used as an aqueous dispersion or solvent-based liquid. Known methods such as spraying, dipping, a roll coater, a gravure coater, a die, a knife coater, and a microgravure coater can be adopted as a method for applying the coating layer. Among them, a roll coater or a microgravure coater is preferable.

The coating layer of the present invention has a sea-island-like microphase-separated structure composed of a fluorine-containing resin and a binder resin.
That is, a phase-separated structure in which islands of a fluorine-containing resin having a diameter of about 0.1 μm are scattered in the sea of the binder resin. The ratio of the fluorine-containing resin and the binder resin in the coating layer is
30 to 80% by weight of fluorine-containing resin and 7 of binder resin
The content is preferably set to 0 to 20% by weight.

The thickness of the coating layer of the present invention is not particularly limited, but is preferably in the range of 0.05 to 50 μm. If the thickness is too small, the thickness unevenness of the applied layer largely affects the release performance, and there is a possibility that a portion where desired release performance cannot be obtained. Also, if it is too thick, a large amount of coating material is required,
The coating layer itself may be brittle.

Further, the coating layer of the present invention may contain known additives such as an antifoaming agent, a coating improver, a thickener, a silicone oil, an antistatic agent, as long as the object of the present invention is not impaired.
An antioxidant, an ultraviolet absorber, a curing agent, a dye, and the like may be included in the coating by mixing.

The release film of the present invention can be suitably applied to the production of a thermosetting resin laminate having blind via holes or buried via holes. In order to manufacture a thermosetting resin laminate containing IVH, a sequential lamination method or the like in which partial laminates subjected to through-hole plating are sequentially stacked is often used.

The substrate of the thermosetting resin laminate is a substrate obtained by impregnating a thermosetting resin with a woven or nonwoven fabric such as a cellulosic fiber or a glass fiber as a base material. In order to bond these substrates to each other or the substrate and a copper foil or the like, a prepreg in which the same kind of material resin as the material used for the substrates is in a semi-cured state is used. substrate,
A thermosetting resin laminate is manufactured by laminating a copper foil, a prepreg, and the like, arranging a release film on both surfaces thereof, and applying heat and pressure with a press hot plate.

The conditions for heating and pressing are as follows: the temperature of the press hot plate is in the range of 170 to 240 ° C., preferably 170 to 200 ° C .; the pressure is 5 to 50 kg / cm ² , preferably 15 to 2
The pressure is in the range of 5 kg / cm ² and the pressurization time is in the range of 30 to 240 minutes, preferably 40 to 120 minutes.

At the time of heating and pressing, nothing may be sandwiched between the release film and the pressing hot plate, and the pressing may be performed in a state where the two are in direct contact with each other. It may be pressed in between. The material of the press hot plate is preferably stainless steel.

[0049]

EXAMPLES Examples 1 to 3 are synthesis examples of a fluorine-containing resin, Examples 4 to
6 is an example of the present invention, and Examples 7 to 9 are comparative examples.

[Examples 1 to 3] The monomers shown in Table 1 were placed in a glass autoclave having an internal volume of 1000 ml and equipped with a stirrer.
Charge the indicated amount (parts by weight) and further add 35 parts of ion-exchanged water.
0 parts by weight, 50 parts by weight of dipropylene glycol monomethyl ether, 12 parts by weight of an emulsifier (polyoxyethylene glycol monolauryl ether), and an amphoteric emulsifier (2-
4 parts by weight of dodecyl-N-carboxyethyl-N-hydroxyethylimidazolium betaine) and 1 part by weight of an azo polymerization initiator (trade name: V-50, manufactured by Wako Pure Chemical Industries, Ltd.) were charged.

The gas phase was replaced with nitrogen gas (when vinyl chloride was used, vinyl chloride was injected under pressure after the replacement), the temperature was raised to 60 ° C. with stirring, and the reaction was carried out for 15 hours. After the polymerization, the polymerization rate of the monomer was determined to be 99 by gas chromatography analysis.
% Was confirmed.

[0052]

[Table 1]

Example 4 A biaxially stretched polyethylene terephthalate having a thickness of 50 μm was subjected to a corona discharge treatment to obtain a film-like support. The polymer of Example 1 and the following hydrophilic urethane resin A were mixed at a solid content weight ratio of 30/70, and adjusted to a solid content of 10% by weight with ion-exchanged water to obtain a coating composition. This coating agent was applied on both sides of the film-like support by a bar coater and dried at 140 ° C. for 3 minutes. A release film having a smooth appearance and a coating layer of 0.5 μm was obtained. When the surface was observed with an electron microscope, a sea-island-like phase-separated structure having a fluorine-containing resin island (approximately 0.1 μm in diameter) in the urethane resin sea was confirmed. Hydrophilic urethane resin A: hydrogenated MDI, IPDI and poly (cyclohexanedimethanol / carbonate)
Reaction product of diol (molecular weight about 100,000).

Example 5 A coating layer having a smooth appearance was prepared in the same manner as in Example 4, except that the polymer of Example 2 and the hydrophilic urethane resin A were mixed at a solids weight ratio of 50/50. A release film of 0.5 μm was obtained. On the surface, the same sea-island-like phase-separated structure as in Example 4 was confirmed.

Example 6 The same procedure as in Example 4 was carried out except that the polymer of Example 3 and the following hydrophilic urethane resin B were mixed at a weight solids ratio of 50/50% by weight as a coating agent, and a smooth appearance was obtained. A release film having a coating layer of 0.5 μm was obtained. On the surface, the same sea-island-like phase-separated structure as in Example 4 was confirmed. Hydrophilic urethane resin B: Reaction product of hydrogenated MDI and poly (1,6-hexylene adipate) diol (molecular weight: about 500,000).

Example 7 A smooth and uniform release film was obtained in the same manner as in Example 4 except that only the polymer of Example 1 was used as a coating agent.

Example 8 The same procedure as in Example 4 was carried out except that only the polymer of Example 2 was used as the coating agent, and a turtle shell-like pattern appeared on the release film as it was dried.

Example 9 A smooth and uniform release film was obtained in the same manner as in Example 4, except that only the hydrophilic urethane resin A was used as a coating agent.

[Evaluation of Film Release Property] Release film (both sides coated) and glass-epoxy prepreg (Sumilite ELC-475, trade name, manufactured by Sumitomo Bakelite Co., Ltd.)
The alternate laminate of 6) was formed, and the laminate was sandwiched between silicone rubbers and put into a hot press. Thereafter, the temperature was raised from room temperature to 180 ° C. over about one hour, and simultaneously, the press pressure was increased to 20 kg / cm ² and maintained for 10 minutes.

When the film is peeled and used, the laminate having a smooth surface after peeling is evaluated as ○, the one with pocked ×, the one with good releasability as 、, the one with partial snagging as ×, and adhered. Are shown as XX.

[Evaluation of Transferability] The surface of the substrate facing the film after curing was analyzed by ECSA, and the intensity ratio was F1s / Br3.
It is indicated by d (however, Br is included in the prepreg).

[0062]

[Table 2]

[0063]

The release film of the present invention is obtained by coating a film-like support with a fluorine-containing resin and a coating layer containing the fluorine-containing resin and a resin forming a sea-island-like microphase-separated structure. Without deteriorating the properties of the film-like support, excellent adhesion between the film-like support and the coating layer,
Moreover, the effect that the coating layer is excellent in releasing property was obtained.

Claims (4)

[Claims] 1. A thermosetting resin laminate having a film-like support coated on at least one side with a coating layer containing a fluorine-containing resin and a resin forming a sea-island-like microphase-separated structure with the fluorine-containing resin. Mold film. 2. The release film for a thermosetting resin laminate according to claim 1, wherein the fluorine-containing resin is a polymer containing a polymerized unit of acrylate or methacrylate having a perfluoroalkyl group. 3. The release film for a thermosetting resin laminate according to claim 1, wherein the binder resin is a urethane resin. 4. A method for producing a thermosetting resin laminate by heating and pressurizing a laminate of thermosetting resin laminate materials between hot plates, wherein a surface of the thermosetting resin laminate material laminate is in contact with the hot plate. 4. A method for producing a thermosetting resin laminate, which is covered with the release film for a thermosetting resin laminate according to claim 1, 2 or 3, and is heated and pressed.