JP4470091B2 - Polyurethane resin composition, laminate and flexible printed wiring board - Google Patents

Description

  The present invention relates to a flame retardant polyurethane resin adhesive, and a flexible printed wiring board using the flame retardant polyurethane resin composition as an adhesive has excellent non-halo flame resistance, adhesion, and solder resistance. .

  In recent years, various thermosetting resins have been used as adhesives for the purpose of improving heat resistance in various fields. For example, an epoxy / acryl butadiene adhesive, an epoxy / polyvinyl butyral adhesive, or the like is used as an adhesive for a circuit board. When used as an adhesive for circuit boards, solder heat resistance and adhesion in a high temperature atmosphere are required.

  In addition, polyester-based resins as structural plastics are used in a wide variety of fields because of the large design range of resin characteristics of the copolymer and recyclability.

  Since these resin compositions are inherently flammable, they require flame safety, that is, flame resistance, in addition to satisfying the general chemical and physical properties in a balanced manner when used as industrial materials. Often done. In particular, in many cases used for home appliances including flexible printed wiring boards, high flame retardancy such as “V-0 by UL standard” is required. In general, as a method of imparting flame retardancy to a resin, a method of adding a halogen-based organic compound as a flame retardant and further adding an antimony compound as a flame retardant assistant to the resin can be mentioned. However, this method has a problem of generating corrosive halogen gas or dioxin during combustion. Therefore, in recent years, in order to eliminate the adverse effects of these halogen-based flame retardants on the environment, it has been strongly desired to use a halogen-free flame retardant that does not contain halogen at all.

  For the halogen-free flame retardant formulation, for example, a phosphorous flame retardant formulation is employed. However, in order to impart flame retardancy with phosphorus-containing additives such as phosphate esters, the resin must be blended in large quantities, and the resin properties such as adhesiveness, heat resistance, and solder resistance are reduced. There is also a problem that the flame retardant bleeds out.

  Therefore, a flame retarding technique by copolymerization of phosphorus compounds has been proposed. For example, in a resin composition formed by blending a flame retardant composed of a linear polymer compound proposed in Patent Document 1 or a flame retardant composed of the linear polymer compound with polystyrene, polycarbonate, polyethylene terephthalate, or the like. Although it is excellent in flame retardancy, it is thermoplastic, so it is inferior in solder resistance, and it is inadequate as an adhesive for flexible wiring boards because it has poor adhesion at room temperature. Further, in the technique proposed in Patent Document 2, the compound obtained by reacting phosphorus compound 1 and hexamethylenetetramine as in Example 1 is excellent in flame retardancy but has poor adhesion at room temperature, and also has solder resistance. Inadequate as an adhesive for a flexible wiring board. That is, even if it is going to apply to an adhesive agent only by these techniques, adhesiveness seems to be insufficient, and it was inadequate for the performance in the field | area where high durability like a flexible wiring board is calculated | required especially.

As described above, the conventional technology has not proposed a flame retardant resin composition that has high flame retardancy under halogen-free conditions and sufficiently satisfies the characteristics as an adhesive or structural plastics. .
JP-A-53-128195 (Claims) JP 63-150352 A (Example 1)

  The present invention not only exhibits excellent flame retardancy without using halogen, but also mechanical performance and thermal stability for adhesives and structural plastics, especially for mechanical parts, electrical / electronic parts and automobile parts. An object is to provide an excellent flame retardant resin composition.

  As a result of intensive research to obtain an adhesive having excellent non-halogen flame retardancy, adhesion and solder resistance, the present inventors have found that when a phosphorus-containing polyurethane resin is used, good non-halogen flame retardant The present invention has been found out that the property, adhesiveness and solder resistance can be obtained. That is, this invention is the following polyurethane resin compositions, laminated bodies, and flexible printed wiring boards.

Ｒ¹、Ｒ²：水素原子、または炭化水素基等
Ｒ³、Ｒ⁴：水素原子、炭化水素基またはヒドロキシ基置換炭化水素基
１、ｍ；０〜４の整数
一般式２；

Ｒ⁵：水素原子、または炭化水素基等
Ｒ⁶、Ｒ⁷：水素原子、炭化水素基またはヒドロキシ基置換炭化水素基 (1) A phosphorus-containing polyester polyol obtained by copolymerizing a phosphorus-containing carboxylic acid represented by the general formula 1 or the general formula 2 or an ester compound thereof as a constituent component and having an acid value of 50 equivalents / 10 ⁶ g or more A polyurethane resin composition comprising a polyurethane resin and an epoxy compound.
General formula 1;

R ¹ , R ² : hydrogen atom, hydrocarbon group or the like R ³ , R ⁴ : hydrogen atom, hydrocarbon group or hydroxy group-substituted hydrocarbon group 1, m; integer general formula 2 of 0-4;

R ⁵ : hydrogen atom, hydrocarbon group or the like R ⁶ , R ⁷ : hydrogen atom, hydrocarbon group or hydroxy group-substituted hydrocarbon group

(2) The polyurethane resin composition according to (1), further comprising a silane coupling agent and / or silica.

Ｒ¹、Ｒ²：水素原子、または炭化水素基等
Ｒ³、Ｒ⁴：水素原子、炭化水素基またはヒドロキシ基置換炭化水素基
１、ｍ；０〜４の整数
一般式２；

Ｒ⁵：水素原子、または炭化水素基等
Ｒ⁶、Ｒ⁷：水素原子、炭化水素基またはヒドロキシ基置換炭化水素基 (3) In a flexible printed wiring board including a configuration of a plastic film layer, a polyurethane resin composition layer, and a metal layer, the polyurethane resin contains a phosphorus-containing carboxylic acid represented by the general formula 1 or 2 or an ester compound thereof. A flexible printed wiring board comprising a phosphorus-containing polyester polyol obtained by polymerization as a constituent and having an acid value of 50 equivalents / 10 ⁶ g or more.
General formula 1;

R ¹ , R ² : hydrogen atom, hydrocarbon group or the like R ³ , R ⁴ : hydrogen atom, hydrocarbon group or hydroxy group-substituted hydrocarbon group 1, m; integer general formula 2 of 0-4;

R ⁵ : hydrogen atom, hydrocarbon group or the like R ⁶ , R ⁷ : hydrogen atom, hydrocarbon group or hydroxy group-substituted hydrocarbon group

(4) A laminate comprising the plastic film layer, the polyurethane resin composition layer according to (1) or (2), and a metal layer.

(5) A flexible printed wiring board comprising a plastic film layer, a polyurethane resin composition layer according to (1) or (2), and a metal layer.

  The present invention relates to a flame retardant polyurethane resin composition, and a flexible printed wiring board using the flame retardant polyurethane resin composition as an adhesive has excellent non-halo flame resistance, adhesion, and solder resistance. To express. Especially for applications such as electronic wiring parts that bond metal and plastic films, compared to conventional flame retardant adhesives, polyurethane resins are flame retardant, so the amount of filler added is small. It is very useful as a flexible printed wiring board adhesive because it can be reduced and the bleed-out of the filler over time can be suppressed without impairing solder resistance and adhesiveness.

  In the polyurethane resin used in the present invention, in order to impart non-halogen flame retardancy, it is essential that a monomer having a phosphorus atom is introduced by copolymerization or modification to include a phosphorus atom in the molecular chain. The amount of phosphorus atoms contained is preferably 0.5 wt% or more, more preferably 1.0 wt% or more, still more preferably 2.0% or more, and most preferably 3.0 wt% or more in the weight of the resin. The upper limit is not particularly limited, but is preferably less than 6.0 wt% because of the possibility that a resin having a predetermined molecular weight cannot be obtained during polymerization. If the phosphorus atom content is less than 0.5 wt%, the flame retardancy is low and it may be difficult to use as a flame retardant adhesive. As a method for introducing a phosphorus atom into these resins, a general method is used. Among them, the phosphorus-containing polyvalent carboxylic acid represented by the above general formula 1 or general formula 2 or an esterified product thereof is particularly used. A method using a polymerized polyester polyol as a urethane resin component is more preferable.

Specific examples of R ¹ , R ² and R ^{5 in} the general formulas 1 and 2 are hydrocarbon groups such as hydrogen atom, methyl, ethyl, propyl and phenyl. R ¹ and R ² may be the same or different. R ⁵ is a hydrogen atom, or a hydrocarbon group such as methyl, ethyl, propyl, or phenyl. R ³ , R ⁴ , R ⁶ and R ⁷ are each a hydrogen atom, methyl, ethyl, propyl, butyl, phenyl, benzyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 4-hydroxybutyl, 2-hydroxy A hydrocarbon group such as ethyloxyethyl or a hydroxy-substituted hydrocarbon group.

  The dibasic acid component used in the phosphorus-containing polyester polyol is not particularly limited, but examples thereof include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid. Aromatic dibasic acids such as phosphoric acid, 4,4′-diphenyldicarboxylic acid, 2,2′-diphenyldicarboxylic acid, 4,4′-diphenyletherdicarboxylic acid, adipic acid, azelaic acid, sebacic acid, 1,4- Examples thereof include aliphatic and alicyclic dibasic acids such as cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, and dimer acid.

  The glycol component used in the phosphorus-containing polyester polyol is not particularly limited, but ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1, 2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neo Pentyl glycol, diethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,5-pentanediol, cyclohexane dimethanol, neopentyl hydroxypivalate, ethylene of bisphenol A Ethylene oxide adduct and propylene oxide adduct, hydrogenated bisphenol A ethylene Oxide adduct and propylene oxide adduct, 1,9-nonanediol, 2-methyloctanediol, 1,10-decanediol, 2-butyl-2-ethyl-1,3-propanediol, tricyclodecanedi Methanol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, or the like can be used.

  As the polyol component raw material of the flame retardant polyurethane, a polyester polyol, a polyether polyol, a polycarbonate polyol or the like is used in combination with the phosphorus-containing polyester polyol as a polyol component other than the phosphorus-containing polyester polyol. It is also possible to do.

  Examples of the isocyanate component used in the flame-retardant polyurethane resin include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-phenylene diisocyanate, diphenylmethane diisocyanate, m-phenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate. Isocyanate, 3,3′-dimethoxy-4,4′biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 2,6-naphthalene diisocyanate, 3,3′-dimethyl-4,4′-diisocyanate, 4,4′- Diisocyanate diphenyl ether, 1,5-xylylene diisocyanate, 1,3 diisocyanate methylcyclohexane, 1,4-diisocyanate methylcyclohexane, isophorone diisocyanate Over doors and the like.

The acid value of the flame-retardant polyurethane resin used in the present invention needs to be 50 equivalents / 10 ⁶ g or more. A preferred lower limit is 80 equivalents / 10 ⁶ g or more, more preferably 100 equivalents / 10 ⁶ g, and most preferably 150 equivalents / 10 ⁶ g. When the acid value of the resin is less than 50 equivalents / 10 ⁶ g, there are cases where the crosslinking reaction point is insufficient and the degree of crosslinking necessary for exhibiting solder resistance may not be obtained. The acid value is preferably 2000 equivalents / 10 ⁶ g or less. When it is higher than 2000 equivalent / 10 ⁶ g, distortion due to cross-linking increases, and adhesiveness may decrease. The acid value referred to here indicates the equivalent number of carboxyl groups per 10 ⁶ g (1 ton) of resin.

  Examples of a method for imparting an acid value to the flame retardant polyurethane resin used in the present invention include a method of synthesizing a flame retardant polyurethane resin using an acid-modified phosphorus-containing polyester polyol, dimethylol propionic acid, and dimethylol. Examples include a method of synthesizing a flame retardant polyurethane resin using butanoic acid or the like as a chain extender. Of these, the latter is preferred in order to adjust the molecular weight to an appropriate level upon polymerization of the polyurethane resin.

  The glass transition temperature of the flame retardant polyurethane resin used in the present invention is preferably −15 ° C. or more and less than 100 ° C. A more preferable lower limit is −10 ° C., and further preferably −5 ° C. A more preferred upper limit is less than 60 ° C, and even more preferred is less than 40 ° C. When the glass transition temperature is less than −15 ° C., the cohesive strength of the phosphorus-containing polyurethane resin is lowered, and solder resistance may be lowered. On the other hand, when the glass transition temperature exceeds 100 ° C., the modulus of elasticity near room temperature becomes high, and the resin itself is too stiff to exhibit adhesiveness to the adherend.

  The number average molecular weight of the flame retardant polyurethane resin used in the present invention is preferably 8000 or more. More preferably, it is 10,000 or more, More preferably, it is 20000 or more. If the number average molecular weight is less than 8000, the mechanical strength is insufficient, and various application properties such as adhesion may be impaired. The upper limit is not particularly limited, but it is preferably 40000 or less, preferably 30000 or less in consideration of economics at the time of polymerization and solution viscosity of the completed adhesive.

  The number average molecular weight of the phosphorus-containing polyester polyol used in the flame-retardant polyurethane resin used in the present invention is preferably 1000 or more. More preferably, it is 2000 or more, More preferably, it is 7000 or more. When the number average molecular weight is lower than 1000, the adhesiveness is lowered. If it is 7000 or more, the distance between crosslinks becomes long, the distortion during crosslinking is alleviated, and high adhesion is obtained. When the number average molecular weight is higher than 20,000, the number of functional groups of isocyanate and hydroxyl group is reduced when making a flame retardant polyurethane resin, and it becomes difficult to control the molecular weight, which is not practical.

  A flame retardant polyurethane resin composition is prepared by blending an epoxy compound using the flame retardant polyurethane resin as described above. When an epoxy compound is blended, the flame retardant polyurethane resin as described above can be cross-linked, heat resistance is improved, solder resistance is excellent, and polyimide films and polyethylene terephthalate films used for flexible printed circuit boards, It is preferable at the point which can express the adhesiveness excellent in copper foil etc.

  Specific examples of the epoxy compound include glycidyl such as bisphenol A diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, bisphenol F diglycidyl ether, dicyclopetadiene, novolac glycidyl ether, and phenol novolac. Glycidyl ester types such as ether type, glycidyl hexahydrophthalate, dimer acid glycidyl ester, triglycidyl isocyanurate, tetraglycidyl diaminodiphenylmethane, metaxylenediamine, hydrogenated metaxylenediamine, or 3,4-epoxy Alicyclic or aliphatic epoxy such as cyclohexyl methyl carboxylate, epoxidized polybutadiene, epoxidized soybean oil, etc. Ido and the like. Among these, dicyclopetadiene, novolac glycidyl ether type, and phenol novolac type epoxy compounds are preferable from the viewpoint of solder resistance and adhesiveness.

  As a compounding quantity of an epoxy compound, when a polyurethane resin is 100 weight%, addition of 1 to 50 weight% is preferable. A preferred upper limit is 40% by weight, and a more preferred upper limit is 30% by weight. On the other hand, a preferred lower limit is 4% by weight, and a more preferred lower limit is 8% by weight. If it exceeds 50% by weight, the adhesive layer may become too hard, resulting in poor adhesion. If it is less than 1% by weight, the degree of crosslinking may be insufficient and solder resistance may be poor.

  A silane coupling agent and / or silica can be further added to the flame retardant polyurethane resin composition of the present invention. By adding a silane coupling agent, the effect of metal adhesion can be obtained, improving adhesion to copper foil and soldering resistance when humidifying, and by adding silica, the elastic modulus is increased and solder resistance is improved. An effect is obtained. Those containing both are most preferred.

  Examples of silane coupling agents include β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycine. Silane coupling agents having a glycidyl functional group such as sidoxypropylmethyldiethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (βmethoxyethoxy) silane, γ-methacryloxy Silane coupling agent having vinyl functional group such as propyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (A Aminoethyl) .gamma.-aminopropyltriethoxysilane, N- phenyl--γ- aminopropyltrimethoxysilane silane coupling agent having an amine functional group such as such include silane coupling agent containing an imidazole group. A silane coupling agent having a glycidyl functional group is preferred. In this case, the blending amount is preferably 0.5 wt% or more and less than 10 wt% with respect to 100 wt% of the polyurethane resin. If the amount is less than 0.5 wt%, the effect of improving adhesiveness and solder resistance may not be obtained. On the other hand, if it is 10 wt% or more, the amount of methanol or ethanol generated by hydrolysis increases, and the adhesion and solder resistance may decrease.

  Silica having an average primary particle diameter of less than 1 μm is preferable. More preferably, it is less than 60 nm. When it is 1 μm or more, the unevenness of the coating surface becomes large, and when used as a cover film or the like as an adhesive for flexible printed wiring boards, the adhesive will not be buried between the pitches between the copper wires. It may not be used as an adhesive for plates. The upper limit is preferably less than 60 nm and more preferably less than 30 nm in terms of embedding properties. Moreover, what made the silica surface hydrophobic by processing agents, such as dimethyldichlorosilane, hexamethyldisilazane, and octylsilane, is preferable.

  In addition, the flame-retardant polyurethane resin composition of this invention can further improve a flame-retardant effect by using a flame retardant together. For example, organic phosphorus flame retardants such as phosphate esters, phosphate amides, organic phosphine oxides, nitrogen flame retardants such as red phosphorus, ammonium polyphosphate, phosphazene, triazine, melamine cyanurate, polystyrene sulfonate alkali metal salts, etc. Metal salt flame retardants, hydrated metal flame retardants such as aluminum hydroxide and magnesium hydroxide, and other inorganic flame retardants. Higher flame retardant effect can be obtained from the combined effect of the flame retardant mechanism of the high flame retardancy of the phosphorus compound-containing resin itself and the flame retardant.

  This flame retardant polyurethane resin composition can use a curing agent such as an isocyanate compound or an acid anhydride, or a curing catalyst such as tin or amine, as necessary.

  Examples of the curing agent for the isocyanate compound include aromatic, alicyclic, and aliphatic diisocyanate compounds, and trivalent or higher polyisocyanate compounds, which may be either low molecular compounds or high molecular compounds. For example, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, or a trimer of these isocyanate compounds, and an excess amount of these isocyanate compounds For example, low molecular active compounds such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine or various polyester polyols, polyether polyols, polymer active hydrogens of polyamides Terminals obtained by reacting with compounds, etc. Isocyanate group-containing compound. These can be used alone or in combination.

  Moreover, when a pot life is required as an adhesive, a blocked isocyanate compound may be used as the isocyanate compound. As isocyanate blocking agents, for example, phenols such as phenol, thiophenol, methylthiophenol, cresol, xylenol, resorcinol, nitrophenol, chlorophenol, oximes such as acetooxime, methyl ethyl ketoxime, cyclohexanone oxime, methanol, ethanol, propanol, Alcohols such as butanol, halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol, tertiary alcohols such as t-butanol and t-pentanol, and lactams such as ε-caprolactam In addition, aromatic methylene compounds such as aromatic amines, imides, acetylacetone, acetoacetic acid ester, malonic acid ethyl ester, mercaptans, imi S, ureas, and also such as diaryl compounds sodium bisulfite. The blocked isocyanate compound is obtained by reacting the isocyanate compound and the blocking agent by a conventionally known method, and each can be used alone or in combination.

  Moreover, the flame retardant polyurethane resin composition of the present invention can be used as an adhesive or a coating agent by mixing various additives. Examples of the additives include crystal nucleating agents such as talc, mica, polyethylene, and various metal salts, coloring pigments, inorganic and fixed fillers, and tackiness improvers in addition to the flame retardants described above.

  An adhesive film can be obtained by dissolving the flame-retardant polyurethane resin composition of the present invention in an organic solvent, and coating and drying on a plastic film. As a dry film thickness, 200 micrometers-3 micrometers are preferable. More preferably, it is 100 micrometers or less, More preferably, it is 70 micrometers or less, and 10 micrometers or more are more preferable.

  As the plastic film, any plastic film such as a polyester film, a polyamide film, a polycarbonate film, a polypropylene film, a polystyrene film, a polyimide film, a polyamide film, and a polyoxabenzazole film is used, but the polyimide film is heat resistant. preferable. The plastic film can be provided with a corona treatment or an easy adhesion layer as necessary.

  The plastic film coated with the flame retardant polyurethane resin composition of the present invention obtained in this manner is laminated with other materials and plastic films, and is heated and pressed to form a laminate. I can do it. As other materials, metals are preferable, and copper foil and copper wire are preferable when used as electric wiring parts and electric circuits. The adhesive containing the phosphorus-containing polyurethane resin of the present invention and the flame-retardant polyurethane resin exhibits excellent adhesiveness to polyimide films and copper foils, so that electrical wiring components using this simultaneously, especially It is very suitable when used as an adhesive for flexible printed wiring boards.

  In addition to the above uses, the flame-retardant polyurethane resin composition of the present invention includes various plastic films such as polyimide and polyester, metal foils such as copper, stainless steel, and aluminum, epoxy-impregnated glass cloth, epoxy-impregnated nonwoven fabric, polyester, It can be used as an adhesive or impregnating resin or coating agent for fibers such as nylon. It can also be applied to flame retardant plastics based on polyester or the like as a structural material.

  In order to describe the present invention in more detail, examples are given below, but the present invention is not limited to the examples. In addition, the measured value described in the Example is measured by the following method. In the examples, “parts” means “parts by weight”.

Composition: The resin was dissolved in deuterated chloroform and quantified by ¹ H-NMR.

  Number average molecular weight: It was determined as a polystyrene equivalent value by gel permeation chromatography using tetrahydrofuran as a solvent.

  Acid value: The resin value was measured by titrating with an ethanol solution of potassium hydroxide after dissolving in chloroform using a coating film from which the solvent was completely removed by vacuum drying at room temperature for 12 hours. A phenolphthalein solution was used as the indicator.

  Glass transition temperature: Using a differential scanning calorimeter, 5 mg of a measurement sample was placed in an aluminum pan, sealed with a lid held down, and measured at a heating rate of 20 ° C./min.

Phosphorus atom content (wet decomposition, determination of phosphorus by molybdenum blue colorimetric method):
The sample was weighed in an Erlenmeyer flask in accordance with the phosphorus concentration in the sample, 3 ml of sulfuric acid, 0.5 ml of perchloric acid and 3.5 ml of nitric acid were added, and the mixture was gradually thermally decomposed with an electric heater over a half day. When the solution becomes clear, it is further heated to produce white sulfuric acid smoke, allowed to cool to room temperature, this decomposition solution is transferred to a 50 ml volumetric flask, 5 ml of 2% ammonium molybdate solution and 2 ml of 0.2% hydrazine sulfate solution. Was added, and the contents were mixed well with pure water. After heating and coloring for 10 minutes in a boiling water bath, water-cooling to room temperature, degassing with ultrasonic waves, taking the solution into an absorption cell 10 mm, and using a spectrophotometer (wavelength 830 nm) to empty test solution Absorbance was measured as a control. The phosphorus content was obtained from the calibration curve prepared previously, and the P concentration in the sample was calculated.

<Synthesis example 1 of phosphorus-containing polyester polyol>
In a reaction vessel equipped with a stirrer, a thermometer, and an outflow cooler, 171 parts of terephthalic acid, 199 parts of isophthalic acid, ethylene glycol solution of formula 3 (solid content 50%) (GHM manufactured by Sanko Co., Ltd.) 1042 parts , 3-methyl-1,5-pentanediol (527 parts), tetrabutyl titanate (0.23 parts) and triethylamine (0.17 parts) were charged, and the esterification reaction was carried out at 180 to 240 ° C. for 1 hour. Next, after the esterification reaction was completed, the temperature of the reaction system was raised from 240 ° C. to 250 ° C., while the pressure inside the system was gradually reduced to 500 Pa over 60 minutes. Then, a polycondensation reaction was further performed at 130 Pa or less for 65 minutes to obtain a phosphorus-containing polyester polyol.

  As a result of NMR analysis, the phosphorus-containing polyester polyol has a composition of terephthalic acid 28 mol%, isophthalic acid 30 mol%, formula 4 component 42 mol%, ethylene glycol 31 mol%, 3-methyl-1,5-pentanediol 69 mol%. It was a pale yellow resin having a number average molecular weight of 3200 and a glass transition temperature of 30 ° C.

<Synthesis Examples 2-3 of Phosphorus-Containing Polyester Polyol, Comparative Synthesis Examples 1-8>
Of the phosphorus-containing polyester polyols synthesized by the same method as “Synthesis Example 1 of Phosphorus-Containing Polyester Polyol”, “Synthesis Examples 2-3 of Phosphorus-Containing Polyester Polyol” is shown in Table 1, and “Comparative Synthesis of Phosphorus-Containing Polyester Polyol” Examples 1 to 8 ”are shown in Table 2.

Formula 3;

Formula 4;

Abbreviations in Tables 1 and 2 are as shown below.
TPA: terephthalic acid IPA: isophthalic acid AA: adipic acid SA: sebacic acid EG: ethylene glycol 2MG: 2-methyl-1,3-propanediol MPD: 3-methyl-1,5-pentanediol 1,6-HD: 1,6-hexanediol

  The numerical values regarding the composition in Tables 1 and 2 are mol%.

<Synthesis example 7 of flame retardant polyurethane resin>
Phosphorus-containing polyester polyol synthesis example 1 In a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a distillation tube, 264 parts of phosphorus-containing polyester polyol was dissolved in 150 parts of toluene, and then 30 parts of toluene was distilled and azeotroped with toluene / water. The raw material system was dehydrated. After cooling to 60 ° C., 66 parts of methyl ethyl ketone, 7.9 parts of dimethylolbutanoic acid, 18.5 parts of neopentyl glycol were added, and after stirring at 60 ° C. for 30 minutes, 50.4 parts of hexamethylene diisocyanate was added, and dibutyltin was added. After adding 0.2 parts of dilaurate, the reaction was carried out at 80 ° C. to obtain a polyurethane resin. After completion of the reaction, 284 parts of methyl ethyl ketone was added to adjust the solid content concentration to 40%. The number average molecular weight of the polyurethane resin was 32,000, the acid value was 180 equivalents / 10 ⁶ g, and the glass transition temperature was 32 ° C. The results are shown in Table 3.

<Synthesis Examples 8-12 of Flame Retardant Polyurethane Resin, Comparative Synthesis Examples 9-16>
Of the flame-retardant polyurethane resins obtained using the raw materials shown in Table 3 and Table 4 in the same manner as in “Flame-retardant polyurethane synthesis example 7”, “Flame-retardant polyurethane resin synthesis examples 8 to 12” Table 3 shows “Comparative Synthesis Examples 9 to 16 of Flame Retardant Polyurethane Resin” in Table 4. “Comparative Synthesis Examples 9 to 16 of flame retardant polyurethane resin” are not copolymerized with phosphorus or have an acid value of less than 100 equivalents / 10 ⁶ g, which is outside the scope of the present invention. “Comparative Synthesis Example 15” and “Comparative Synthesis Example 16” are comparative synthesis examples 7 and 8, which are phosphorus-containing polyester polyols, in a mixed solvent (1/1 weight ratio) of methyl ethyl ketone and toluene with a solid content concentration of 40%. This was dissolved and used as it was. Since “Comparative Synthesis Example 15” is a polyester polyol, it is out of the scope of the present invention. “Comparative Synthesis Example 16” is a polyester polyol that does not contain phosphorus and does not contain a urethane group, and thus is outside the scope of the present invention.

Abbreviations in Tables 3 and 4 are as follows.
DMPA: dimethylolpropionic acid DMBA: dimethylolbutanoic acid NPG: neopentyl glycol HDI: hexamethylene diisocyanate MDI: diphenylmethane diisocyanate

<Example 1>
Benzophenone tetracarboxylic dianhydride 3 parts flame retarded polyurethane resins 1 00 parts of the obtained and Tohto Kasei Co., Ltd. YDCN703 (o-cresol novolac type epoxy resin) 13 parts of Synthetic Example 7 was added, stirred The dissolution was performed. Furthermore, 20 parts of MC-640 (melamine cyanurate) manufactured by Nissan Chemical Co., Ltd., 5 parts of CoatOSil 1770 (β- (3,4-epoxycyclohexyl) ethyltriethoxysilane) manufactured by Nippon Unicar Co., Ltd., Nippon Aerosil Co., Ltd. ) 3 parts R972 (silica, primary average particle size 16 nm) manufactured by the company, and adjusted by adding methyl ethyl ketone to a solid content concentration of 40%, sufficiently stirring and dispersing to obtain the desired adhesive solution It was. This solution was applied to a 25 μm polyimide film so that the thickness after drying was 30 μm, and dried at 120 ° C. for 3 minutes. When the adhesive film obtained in this manner is bonded to the rolled copper foil, the glossy surface of the rolled copper foil is in contact with the adhesive and pressed at 140 ° C. under a pressure of 5 kg / cm ² for 1 minute. Glued. The obtained adhesion sample was cured by heat treatment at 150 ° C. for 4 hours. The samples thus obtained were measured for solder resistance, peel strength at 25 ° C., and peel strength at 100 ° C. Each evaluation method was performed as follows.

Normal-state solder resistance: The sample was dried at 120 ° C. for 30 minutes and then immersed in a 300 ° C. solder bath for 10 seconds to confirm the appearance.
(Judgment) ○: No abnormality at all
Δ: Swelling occurs in some areas
×: Fully swollen

Humidification and soldering resistance: The sample was humidified at 40 ° C. × 80% for 3 days and then immersed in a solder bath at 260 ° C. for 10 seconds to confirm the appearance.
(Judgment) ○: No abnormality at all
Δ: Swelling occurs in some areas
×: Fully swollen

Peel strength at 25 ° C. and 100 ° C .: 90 ° peeling was performed at a pulling rate of 100 mm / min.

Evaluation of flame retardancy: A 25 μm polyimide film was applied so that the thickness after drying was 30 μm, dried at 120 ° C. for 3 minutes, and then heat treated at 150 ° C. for 4 hours to cure the sample. Created. This was evaluated using a test piece having a length of 125 mm and a width of 12.5 mm based on Subject No. 94 (UL94) standardized by US Underwriters Laboratories (UL).
(Decision) ○: Passed in flame retardant class V-0
X: Those which did not pass are shown in Table 5, and the evaluation results are shown in Table 7.

<Examples 2 to 3 and Comparative Examples 1 to 11 >
Examples 2 to 3 and Comparative Examples 1 to 11 were performed in the same manner as in Example 1.
Table 5 shows the composition of Examples 2-3 and Comparative Examples 9-11 , and Table 7 shows the evaluation results.
Table 6 shows the compositions of Comparative Examples 1 to 8, and Table 8 shows the evaluation results.

  According to Table 7, it can be seen that the flame-retardant polyurethane resin composition of the present invention is excellent in flame retardancy, has both adhesiveness and blocking resistance, and is excellent in mechanical properties such as flex resistance. On the other hand, as seen in Table 8, in Comparative Examples 1, 2, and 3, the acid value is low, so the solder resistance and adhesion are low. In Comparative Example 4, since the glass transition temperature is high, the adhesiveness at 25 ° C. is poor. Moreover, since the acid value is low, the solder resistance is considerably low. In Comparative Examples 5 and 6, since no phosphorus compound is contained, the flame retardancy is considerably low. In Comparative Example 7, since the acid value is low, the solder resistance is considerably low. In Comparative Example 8, since the phosphorus compound is not contained, the flame retardancy is considerably low, and the solder resistance is considerably low because the acid value is low.

The laminate using the flame retardant polyurethane resin composition of the present invention as an adhesive exhibits excellent non-halo flame retardancy, adhesion, and solder resistance.
Especially for applications such as electronic wiring parts that bond metal and plastic films, compared to conventional flame retardant adhesives, polyurethane resins are flame retardant, so the amount of filler added is small. It is very useful as a flexible printed wiring board adhesive because it can be reduced and the bleed-out of the filler over time can be suppressed without impairing solder resistance and adhesiveness.

Claims (4)

A polyurethane resin containing, as a constituent component, a phosphorus-containing polyester polyol obtained by copolymerizing a phosphorus-containing carboxylic acid represented by the general formula 1 or the general formula 2 or an ester compound thereof, and an acid value of 50 equivalents / 10 ⁶ g or more; A polyurethane resin composition for an adhesive, comprising an epoxy compound, a silane coupling agent having a glycidyl functional group, and silica.
General formula 1;

R ¹ , R ² : hydrogen atom or hydrocarbon group R ³ , R ⁴ : hydrogen atom, hydrocarbon group or hydroxy group-substituted hydrocarbon group 1, m; integer general formula 2 of 0-4;

R ⁵ : hydrogen atom or hydrocarbon group R ⁶ , R ⁷ : hydrogen atom, hydrocarbon group or hydroxy group-substituted hydrocarbon group   Furthermore, the polyurethane resin composition of Claim 1 containing a nitrogen-type flame retardant. Crosslinked plastic film layer, a layer consisting of those obtained by crosslinking the polyurethane resin composition according to claim 1 or 2, viewed including the configuration of the metal layer, and the plastic film layer and the metal layer is the polyurethane resin composition Laminate bonded by a layer made of Crosslinked plastic film layer, a layer consisting of those obtained by crosslinking the polyurethane resin composition according to claim 1 or 2, viewed including the configuration of the metal layer, and the plastic film layer and the metal layer is the polyurethane resin composition A flexible printed wiring board bonded by a layer made of the above .