JP2007204589A - Carboxy group-containing polyurethane, thermosetting polyurethane resin composition, and application thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carboxy group-containing polyurethane capable of providing a cured product having excellent adhesion to a base material, low warpage, flexibility, tacking properties, plating resistance, heat resistance at soldering, long-term reliability and flame retardancy. <P>SOLUTION: The carboxy group-containing polyurethane has a structure derived from a phosphorus-containing diol compound having 200-500 mg-KOH/g hydroxy value, and is obtained, for example, by reacting (A) a polyisocyanate compound, (B) a phosphorus-containing diol compound having 200-500 mg-KOH/g hydroxy value, and (D) a carboxy group-containing dihydroxy compound. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a carboxyl group-containing polyurethane and a thermosetting polyurethane resin composition, and more specifically, adhesion to a substrate, low warpage, flexibility, tackiness, plating resistance, solder heat resistance, and long-term reliability. The present invention relates to a carboxyl group-containing polyurethane that gives a cured product having excellent properties and a thermosetting polyurethane resin composition containing the polyurethane.

  Conventionally, as a surface protection film for flexible wiring circuits, a type of polyimide film called a coverlay film that has been punched into a pattern and then pasted using an adhesive, or UV-cured with flexibility There is a type in which a mold or a thermosetting type overcoat agent is applied by a screen printing method, and the latter is particularly useful in terms of workability.

  As such a curing type overcoat agent, a resin composition mainly composed of an epoxy resin system, an acrylic resin system, or a composite system thereof is known. In many cases, these resins are mainly composed of a resin having undergone modification such as introduction of a butadiene skeleton, a siloxane skeleton, a polycarbonate diol skeleton, a long-chain aliphatic skeleton, or the like. As a result, while suppressing the deterioration of heat resistance, chemical resistance and electrical insulation inherent in the surface protective film as much as possible, improvement in flexibility and suppression of warpage due to curing shrinkage and heat shrinkage have been attempted.

  However, in recent years, with the reduction in weight and size of electronic devices, flexible substrates have also become lighter and thinner, and the effects of the flexibility and curing shrinkage of the resin composition to be overcoated are becoming more prominent. Therefore, at present, the curing type overcoat agent cannot satisfy the required performance in terms of warping due to flexibility and curing shrinkage. Various studies have been conducted to solve the current problems.

  For example, Japanese Patent Application Laid-Open No. 2004-137370 (Patent Document 1) discloses a dimerisocyanate polyurethane obtained by reacting a polycarbonate diol and a diisocyanate compound using a diol having 6 or less carbon atoms as a raw material, and trimellitic anhydride. Is disclosed. However, there is a drawback that the long-term reliability of the electrical properties of the cured product is not sufficient.

  Further, such a thermosetting composition is required to satisfy various physical properties depending on the application. In particular, when electronic parts are used, in addition to heat resistance, insulation, flexibility and the like, flame retardancy is required as an important physical property. If the flame retardance is low, the use is limited.

However, it has not been easy to provide sufficiently high flame retardancy with conventional thermosetting compositions. As a method for imparting flame retardancy, there has conventionally been a method using a flame retardant system comprising a halogenated flame retardant such as brominated epoxy resin or a flame retardant aid such as antimony trioxide. JP-A-9-325490 (Patent Document 2), JP-A-11-242331 (Patent Document 3), etc.). However, these flame retardant systems may have poor reliability in high temperature environments. Furthermore, the brominated epoxy resin has a problem that the flexibility of the resin composition is impaired when an amount that provides a sufficient flame retardant effect is added. In recent years, starting with the dioxin problem, decabrom ether and halogenated resins are also being regulated. There is also a demand for dehalogenation and deantimony conversion of resin molding materials used for electronic parts. From this point of view, there is a limit to the improvement of the flame retardant effect by blending the conventional flame retardant.

  In addition, resin compositions using phosphoric acid esters as flame retardants have also been proposed (Japanese Patent Application Laid-Open No. 9-235449 (Patent Document 4), Japanese Patent Application Laid-Open No. 10-306201 (Patent Document 5), and Japanese Patent Application Laid-Open No. 11-2010. No. 271967 (Patent Document 6), etc., has a weak flame-retardant effect only by adding a phosphate ester to the composition, and cannot sufficiently satisfy the flame-retardant standard according to the UL standard. Therefore, it has been desired to develop a thermosetting composition that can achieve dehalogenation and deantimonization and has higher flame retardancy.

Japanese Patent Laid-Open No. 2005-290134 (Patent Document 7) discloses a phosphorus-containing urethane compound and a resin composition containing the compound, and Japanese Patent Application Laid-Open No. 2003-212594 (Patent Document 8) uses a phosphorus atom as a skeleton. A phosphorus-containing urethane (meth) acrylate compound and a resin composition containing the compound are described, and it is also described that each compound exhibits a flame-retarding effect. Among these, although the cured product formed from the resin composition described in Patent Document 8 has sufficient flame retardancy, further improvement in insulation resistance has been desired.
JP 2004-137370 A JP-A-9-325490 JP-A-11-242331 JP 9-235449 A Japanese Patent Laid-Open No. 10-306201 JP 11-271967 A JP-A-2005-290134 Japanese Patent Laid-Open No. 2003-212954

  The present invention is intended to solve the above-described problems in the prior art, has flame retardancy, adhesion to a substrate, low warpage, flexibility, tackiness, plating resistance, solder Carboxyl group-containing polyurethane capable of forming a cured product having excellent heat resistance and long-term reliability, thermosetting polyurethane resin composition containing the carboxyl group-containing polyurethane, and solder resist ink or overcoat containing the resin composition An object is to provide a coating ink.

  Another object of the present invention is to provide a cured product excellent in flame retardancy, adhesion to a substrate, low warpage, flexibility, tackiness, plating resistance, solder heat resistance and long-term reliability. And

  The present inventors have intensively studied to solve the above problems. As a result, it has been found that the above problem can be solved by using a carboxyl group-containing polyurethane having a specific phosphorus skeleton structure, and the present invention has been completed. That is, the present invention relates to the following matters.

[1]
A carboxyl group-containing polyurethane having a structure derived from a phosphorus-containing diol compound (B) having a hydroxyl value of 200 to 500 mg-KOH / g.

[2]
The carboxyl group-containing polyurethane according to [1], wherein the phosphorus-containing diol compound (B) is a compound represented by the following general formula (1);

[In the formula (1), each R ₁ independently represents an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms or an arylalkyl group, and The carbon-carbon bond contained in the group may be replaced with an ether bond or an ester bond, and the hydrogen atom contained in these groups may be replaced with a hydroxyl group.

Each R ₂ independently represents a methylene group or an alkylene group having 2 to 18 carbon atoms;
The carbon-carbon bond contained in these groups may be replaced with an ether bond or an ester bond, and the hydrogen atom contained in these groups may be replaced with a hydroxyl group. ].

[3]
(A) a polyisocyanate compound,
(B) a phosphorus-containing diol compound having a hydroxyl value of 200 to 500 mg-KOH / g,
And (D) the carboxyl group-containing polyurethane according to [1] or [2], which is obtained by reacting a carboxyl group-containing dihydroxy compound.

[4]
Along with the polyisocyanate compound (A), the phosphorus-containing diol compound (B) and the dihydroxy compound (D), (C) a diol compound [however, the diol compound (B) and the dihydroxy compound (D) are excluded. ] The carboxyl group-containing polyurethane according to [3], which is obtained by reacting at least one of (E) a monohydroxy compound and (F) a monoisocyanate compound.

[5]
More than 10 mol% of the polyisocyanate compound (A) (the total amount of the compound (A) is 100 mol%) is an isocyanate group having 6 to 30 carbon atoms (excluding the number of carbon atoms in the isocyanate group). The carboxyl group-containing polyurethane according to [3], which is an aromatic compound and / or an isocyanate group-containing alicyclic compound.

[6]
[4] The diol compound (C) is at least one compound selected from the group consisting of a diol compound having 2 to 18 carbon atoms, a polyether diol, a polyester diol, and a polycarbonate diol. Carboxyl group-containing polyurethane.

[7]
The carboxyl group-containing polyurethane described in [3], wherein the dihydroxy compound (D) is 2,2-dimethylolpropionic acid or 2,2-dimethylolbutanoic acid.

[8]
The monohydroxy compound (E) is at least one selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol and t-butanol, glycolic acid and hydroxypivalic acid. The carboxyl group-containing polyurethane according to [4], which is a compound.

[9]
The monoisocyanate compound (F) is a phenyl isocyanate, hexyl isocyanate, dodecyl isocyanate, and diisocyanate compound methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, amyl alcohol. The carboxyl group-containing polyurethane according to [4], which is at least one compound selected from the group consisting of mono-adducts of hexyl alcohol or octyl alcohol.

[10]
[3] The phosphorus-containing diol compound (B) is used in an amount in the range of 20 to 95 mol% with respect to 100 mol% of the total amount of the compounds (B) and (D). Carboxyl group-containing polyurethane.

[11]
The phosphorus-containing diol compound (B) is used in an amount in the range of 20 to 95 mol% with respect to 100 mol% of the total amount of the compounds (B), (C) and (D) [4 ] The carboxyl group-containing polyurethane as described in any of the above.

[12]
The number average molecular weight is 1,000 to 100,000, and the acid value is 5 to 120 mg-K.
The carboxyl group-containing polyurethane according to any one of [1] to [11], which is OH / g.

[13]
The number average molecular weight is 3,000 to 50,000, and the acid value is 10 to 70 mg-KO.
The carboxyl group-containing polyurethane according to any one of [1] to [12], which is H / g.

[14]
It contains the carboxyl group-containing polyurethane according to any one of the above [1] to [13] and a solvent having a boiling point of 120 ° C. or higher, and the carboxyl group-containing polyurethane is dissolved in the solvent. A thermosetting polyurethane resin composition.

[15]
The solvent is toluene, xylene, ethylbenzene, nitrobenzene, isophorone, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, dipropylene glycol methyl. Ether acetate, dipropylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol methyl ether acetate, methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, ethyl ethoxypropionate, acetic acid n-
The thermosetting polyurethane resin composition according to [14], which is at least one selected from the group consisting of butyl, isoamyl acetate, ethyl lactate, cyclohexanone, γ-butyrolactone, and dimethyl sulfoxide.

[16]
Solid content concentration is 30-80 mass%, The thermosetting polyurethane resin composition as described in [14] or [15] characterized by the above-mentioned.

[17]
[14] A solder resist ink comprising the thermosetting polyurethane resin composition according to any one of [16] and an epoxy resin.

[18]
[14] An overcoat ink comprising the thermosetting polyurethane resin composition according to any one of [16] and an epoxy resin.

[19]
A cured product obtained by curing the solder resist ink according to [17] or the overcoat ink according to [18].

  The carboxyl group-containing polyurethane having a phosphorus skeleton of the present invention has low adhesion to a conveying jig while improving flexibility, and can improve productivity, flame retardancy, adhesion to a substrate, and low warpage. It is suitable as a raw material for a cured product excellent in flexibility, plating resistance, solder heat resistance and long-term reliability, for example, a cured film.

  When the carboxyl group-containing polyurethane and the thermosetting polyurethane resin composition of the present invention are used as resist inks, they can be produced at a lower cost than conventionally used liquid polyimide inks.

  Further, a protective film formed from a conventional resist ink has a large amount of curing shrinkage and cooling shrinkage after curing, causing warping, which causes a decrease in yield. In contrast, when the resist ink of the present invention is used, a protective film excellent in long-term insulation reliability at high temperature and high humidity, which has a trade-off relationship with low warpage, can be formed at low cost with high productivity. Excellent tack, plating resistance and solder heat resistance can be achieved at the same time.

Hereinafter, the carboxyl group-containing polyurethane and thermosetting polyurethane resin composition according to the present invention will be described in detail.
[Carboxyl group-containing polyurethane]
The carboxyl group-containing polyurethane of the present invention has a structure derived from a silicone-containing diol compound having a hydroxyl value of 200 to 500 mg-KOH / g. A structure (phosphorus skeleton) derived from such a phosphorus-containing diol compound can be introduced using a phosphorus-containing diol compound represented by the following formula (1).

[In the formula (1), each R ₁ independently represents an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group or arylalkyl group having 7 to 20 carbon atoms, or These represent an organic group having 2 to 20 carbon atoms having an ether bond and / or an ester bond in the group, and a hydrogen atom contained in these groups may be replaced by a hydroxyl group.

Each R ₂ independently represents a methylene group, an alkylene group having 2 to 18 carbon atoms, or an organic group having 2 to 18 carbon atoms having an ether bond and / or an ester bond, and the hydrogen atoms contained in these groups are It may be replaced with a hydroxyl group. ].

  The carboxyl group-containing polyurethane of the present invention includes (A) a polyisocyanate compound, (B) a phosphorus-containing diol compound having a hydroxyl value of 200 to 500 mg-KOH / g, and (D) a carboxyl group-containing dihydroxy compound, as necessary. It is preferable to synthesize by reacting at least one of (C) a diol compound, (E) a monohydroxy compound and (F) a monoisocyanate compound. Hereinafter, each component will be described.

(A) Polyisocyanate compound:
Examples of the polyisocyanate compound (A) used in the present invention include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, isophorone diisocyanate, 1,6-hexamethylene diisocyanate, and 1,3-trimethylene diisocyanate. 1,4-tetramethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 1,9-nonamethylene diisocyanate, 1,10-decamethylene diisocyanate, 1,4 Cyclohexane diisocyanate, 2,2′-diethyl ether diisocyanate, diphenylmethane-4,4′-diisocyanate, (o, m or p) -xylene diisocyanate, methylene bis (4-cyclo Xyl isocyanate), cyclohexane-1,3-dimethylene diisocyanate, cyclohexane-1,4-dimethylene diisocyanate, 1,5-naphthalene diisocyanate, p-phenylene diisocyanate, 3,3'-methylene ditolylene-4,4'- Examples include diisocyanates such as diisocyanate, 4,4′-diphenyl ether diisocyanate, tetrachlorophenylene diisocyanate, norbornane diisocyanate, and hydrogenated (1,3- or 1,4-) xylylene diisocyanate. These may be used alone or in combination of two or more.

  The number of isocyanate groups per molecule of the polyisocyanate compound (A) is usually 2, but within a range where the carboxyl group-containing polyurethane of the present invention does not gel, 3 or more isocyanate groups such as triphenylmethane triisocyanate are used. A small amount of polyisocyanate can also be used.

Among the above polyisocyanate compounds, when an aromatic compound and / or an alicyclic compound having 6 to 30 carbon atoms (excluding the number of carbon atoms in the isocyanate group (NCO group)) is used, a long period of time at high temperature and high humidity. A cured product exhibiting excellent performance in terms of insulation reliability can be obtained. These aromatic compounds and / or alicyclic compounds are contained in an amount of 10 mol% or more, preferably 20 mol%, more preferably 30 mol% or more based on the total amount (100 mol%) of the polyisocyanate compound (A). Is desirable.

  Examples of the isocyanate group-containing aromatic compound and alicyclic compound include 1,4-cyclohexane diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), cyclohexane-1,3-dimethylene diisocyanate, and cyclohexane-1,4-di. Methylene diisocyanate, hydrogenated (1,3- or 1,4-) xylylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, and diphenylmethane-4,4′-diisocyanate are preferred.

(B) Phosphorus-containing diol compound:
The hydroxyl value of the phosphorus-containing diol compound (B) used in the present invention is 200 to 500 mg-KOH / g. As the phosphorus-containing diol compound (B), a compound represented by the following formula (1) is preferably used. It is done.

In the formula (1), each R ₁ independently represents an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms or an arylalkyl group, and these groups The carbon-carbon bond contained in may be replaced with an ether bond or an ester bond, and the hydrogen atom contained in these groups may be replaced with a hydroxyl group.

Each R ₂ independently represents a methylene group or an alkylene group having 2 to 18 carbon atoms;
The carbon-carbon bond contained in these groups may be replaced with an ether bond or an ester bond, and the hydrogen atom contained in these groups may be replaced with a hydroxyl group.

The alkyl group represented by R ₁ in the above formula (1) is preferably a linear alkyl group which may have a branch. Specific examples include methyl, ethyl, n-propyl, isopropyl, n -Butyl, sec-butyl, isobutyl, tert-butyl, pentyl, isopentyl, tert-pentyl, hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, tert-octyl, nonyl, isononyl, tert-nonyl, decyl, isodecyl, dodecyl , Tridecyl, isotridecyl, tetradecyl, hexadecyl, octadecyl, and the like.

When R ₁ is an aryl group, specific examples thereof include phenyl, naphthyl, anthracenyl, biphenyl, quinolyl and the like;
When R ₁ is an alkylaryl group, specific examples thereof include an aryl group substituted with the above exemplified alkyl group such as a methylphenyl group;
When R ₁ is an arylalkyl group, specific examples thereof include benzyl, α-methylbenzyl, α, α-dimethylbenzyl and the like.

Examples of the alkylene group represented by R ₂ in the formula (1), preferably an alkylene group having 2 to 6 carbon atoms, specifically ethylene, (n- or an iso-) propylene, (n-, sec- , Iso- or tert-) butylene and the like.

  Specific examples of the phosphorus-containing diol compound (B) include diisopropyl-N, N-bis (2-hydroxyethyl) aminomethylphosphonate, diisobutyl-N, N-bis (2-hydroxyethyl) aminomethylphosphonate, dioctyl-N. , N-bis (2-hydroxyethyl) aminomethylphosphonate, dioctadecyl-N, N-bis (2-hydroxyethyl) aminomethylphosphonate, diethyl-N, N-bis (2-hydroxyethyl) aminomethylphosphonate, diethyl -N, N-bis [2- (2-hydroxyethoxy) ethyl] aminomethylphosphonate, diethyl-N, N-bis [ω- (2-hydroxy) polyethoxyethyl] aminomethylphosphonate, diethyl-N, N- Bis (2-hydroxypropyl) aminomethylphospho Honeto, and the like. Among them, preferable examples include diethyl-N, N-bis (2-hydroxyethyl) aminomethylphosphonate commercially available as “ADEKA POLYOL FC-450” from Asahi Denka Kogyo Co., Ltd.

  The phosphorus-containing diol compound (B) is based on the total amount of the diol compound, that is, the compounds (B) and (D) (if the compound (C) is used, the compounds (B) and (C) And (D)) is preferably used in an amount ranging from 20 to 95 mol%, more preferably from 20 to 90 mol%, more preferably from 50 to 80 mol%, based on 100 mol% of the total amount. If the amount of the compound (B) used is less than the above range, the effect of the present invention may not be exhibited. On the other hand, if the amount used exceeds the above range, the amount of the compound (D) used decreases, so The crosslinking point in the group-containing polyurethane may be insufficient, and the solvent resistance of the cured product may decrease, or the thermosetting polyurethane resin composition of the present invention may cause printing defects such as repellency.

(C) Diol compound:
In the present invention, it is preferable to use a diol compound (C) (excluding the phosphorus-containing diol compound (B) and a carboxyl group-containing dihydroxy compound (D) described later). As the diol compound (C), those having a low molecular weight to an oligomer diol having a number average molecular weight of 300 to 50,000 can be used. By using such a diol compound (C), a cured product having good adhesion can be obtained. The number average molecular weight is calculated from the value obtained by measuring the hydroxyl value.

Examples of the diol compound (C) include ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,2-butanediol, 1,3-butanediol, , 4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,8-octanediol, 1,8-octanediol, 1, 9-nonanediol, tricyclo [5.2.1.0] decanedimethanol, pentacyclopentadecanedimethanol,
1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,2-benzene Dimethanol, 1,3-benzenedimethanol, 1,4-benzenedimethanol, 2,3-dihydroxynorbornane, 2,5-dihydroxynorbornane, 2,6-dihydroxynorbornane, 2,7-dihydroxynorbornane, dihydroxydicyclo Diols such as pentadiene and hydrogenated bisphenol A, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, 2,2-bis [4- (2-hydroxyethyloxy) cyclohexyl] propaline , 1,4-bis (2-hydroxyethyl-oxy) number 2 to 18 of the diol compounds carbons such diols containing ether groups benzene.

  In addition, as the oligomer diol, polycarbonate diol represented by the following formula (2) derived from diol having 4 to 12 carbon atoms, polyether diol derived from diol having 2 to 6 carbon atoms, hydroxylation at both ends Examples thereof include polyesters derived from polybutadiene, dicarboxylic acids having 4 to 18 carbon atoms, and diols having 2 to 18 carbon atoms. In these, it is preferable to use polycarbonate diol from a viewpoint of a softness | flexibility or an electrical property heat resistance.

In formula (2), R is a residue after removing the OH group from the raw material diol HO—R—OH, and a plurality of R may be the same or different from each other. M is a positive integer.
The diol compound (C) may be used singly or in combination of two or more. Moreover, the said diol compound (C) can be used in the quantity of the range which does not prevent the performance expression of the said phosphorus containing diol (B).

(D) Carboxyl group-containing dihydroxy compound:
In the present invention, the carboxyl group-containing dihydroxy compound (D) is used for introducing a carboxyl group into polyurethane. By using the carboxyl group-containing dihydroxy compound (D), a crosslinking point can be introduced into the side chain of the polyurethane resin, such as a cured film having better heat resistance than a resin having a crosslinking point introduced at the end of the molecular chain. A cured product can be obtained.

  Examples of the carboxyl group-containing compound (D) include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, N, N-bishydroxyethylglycine, N, N-bishydroxyethylalanine and the like. Can be mentioned. Among these, 2,2-dimethylolpropionic acid and 2,2-dimethylolbutanoic acid are preferable from the viewpoint of solubility in a solvent. The said dihydroxy compound (D) may be used individually by 1 type, or may be used in combination of 2 or more type.

(E) Monohydroxy compound and (F) Monoisocyanate compound:
The carboxyl group-containing polyurethane of the present invention can be synthesized from only the four components (A), (B), (C) and (D), but the purpose is to eliminate the influence of the isocyanate residue and hydroxyl group at the end of the polyurethane. Then, the monohydroxy compound (E) and / or the monoisocyanate compound (F) may be further reacted.

  Moreover, as a monohydroxy compound (E) used for the purpose of eliminating the influence of the isocyanate residue at the terminal of the polyurethane of the present invention, in addition to the above monohydroxy compound, for example, methanol, ethanol, n-propanol, isopropanol, n Examples include -butanol, isobutanol, sec-butanol, t-butanol, amyl alcohol, hexyl alcohol, octyl alcohol, and the like, and carboxylic acid group-containing compounds such as glycolic acid and hydroxypivalic acid.

Moreover, as a monoisocyanate compound (F) used for the purpose of eliminating the influence of the hydroxyl group residue at the end of the polyurethane, phenyl isocyanate, hexyl isocyanate, dodecyl isocyanate, and methanol, ethanol, n-propanol, isopropanol to diisocyanate compound, Examples thereof include mono-adducts of n-butanol, isobutanol, sec-butanol, t-butanol, amyl alcohol, hexyl alcohol or octyl alcohol.
The said compound (E) and / or (F) may be used individually by 1 type, or may be used in combination of 2 or more type.

<Physical properties of carboxyl group-containing polyurethane>
The number average molecular weight (Mn) of the carboxyl group-containing polyurethane of the present invention is preferably 1,000 to 100,000, more preferably 3,000 to 50,000, and particularly preferably 3,000 to 10,000. It is. Here, the number average molecular weight is a value in terms of polyethylene glycol and polyethylene oxide measured by gel permeation chromatography (GPC). When the molecular weight is lower than the above range, the elongation, flexibility and strength of the cured film may be impaired. On the other hand, when the molecular weight exceeds the above range, the solubility of the polyurethane in the solvent becomes low, and the viscosity does not increase even when dissolved. Since it becomes too high, restrictions in use may increase. In addition, unless otherwise indicated, the measurement conditions of GPC in this invention are as follows.

(GPC measurement conditions)
Apparatus name: “HPLC unit HSS-2000” manufactured by JASCO Corporation
Column: Shodex column KD-802, 802.5, 805
Mobile phase: N, N-dimethylformamide Flow rate: 1.0 mL / min
Detector: “RI-2031Plus” manufactured by JASCO Corporation
Temperature: 40.0 ° C
Sample amount: Sample loop 100 μl Sample concentration: Prepared at around 0.1 wt%.

The acid value of the carboxyl group-containing polyurethane of the present invention is preferably 5 to 120 mg-KO.
H / g, more preferably 10 to 70 mg-KOH / g. If the acid value is lower than the above range, the reactivity with other curable resins such as epoxy resins may be reduced and heat resistance may be impaired. On the other hand, if it exceeds the above range, the cured film may be too hard and brittle. is there. In addition, the acid value of the resin in the present invention is a value measured by the following method.

(Method for measuring acid value of resin)
About 0.2 g of a sample is precisely weighed in a 100 ml Erlenmeyer flask with a precision balance, and 10 mL of a mixed solvent of ethanol / toluene = 1/2 (mass ratio) is added and dissolved therein. Further, 1 to 3 drops of phenolphthalein ethanol solution is added to this container as an indicator, and the mixture is sufficiently stirred until the sample becomes uniform. This is titrated with a 0.1N potassium hydroxide-ethanol solution, and the end point of neutralization is defined as the time when the indicator is slightly red for 30 seconds. From the result, the acid value of the resin is calculated using the following formula.

Acid value (mg-KOH / g) = [B × f × 5.611] / S
B: Amount of use of 0.05N potassium hydroxide-ethanol solution (mL)
f: Factor of 0.05N potassium hydroxide-ethanol solution S: Amount of sample collected (g).

The carboxyl group-containing polyurethane of the present invention is preferably a carboxyl group-containing polyurethane having a number average molecular weight of 1,000 to 100,000 and an acid value of 5 to 120 mg-KOH / g, and a number average molecular weight of 3 More preferred is a carboxyl group-containing polyurethane having an acid value of from 10 to 70 mg-KOH / g.

<Method for producing carboxyl group-containing polyurethane>
The carboxyl group-containing polyurethane of the present invention is prepared by using the above-mentioned compounds (A), (B) and (D) using a suitable organic solvent in the presence or absence of a known urethanization catalyst such as dibutyltin dilaurate. Can be synthesized by reacting with at least one of the compounds (C), (E), and (F) as necessary, but the reaction can be performed without a catalyst to finally use as a cured film. The physical property value when it is improved.

  The organic solvent can be used as long as it has low reactivity with isocyanate, has a boiling point of 30 ° C. or higher, preferably 120 ° C. or higher. When the polyurethane of the present invention is formed by screen printing or the like, A solvent having a temperature of 200 ° C. or higher is desirable.

  Examples of such solvents include toluene, xylene, ethylbenzene, nitrobenzene, cyclohexane, isophorone, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl. Ether acetate, dipropylene glycol methyl ether acetate, dipropylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol methyl ether acetate, methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, ethyl ethoxypropionate Ethyl acetate, n-butyl acetate, isoamyl acetate, ethyl lactate, acetone, methyl ethyl ketone, cyclohexanone, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, γ-butyrolactone, dimethyl sulfoxide, chloroform and methylene chloride Etc.

  Among these, propylene glycol methyl ether acetate, propylene glycol ethyl are preferable in view of the fact that the organic solvent having low solubility of the resulting carboxyl group-containing polyurethane is not preferable, and considering that polyurethane is used as a raw material for ink in electronic material applications. Ether acetate, dipropylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, and γ-butyrolactone are preferred.

  In addition, it is necessary to use a solvent with a high boiling point to some extent in screen printing, but when it is necessary to use a low boiling solvent as a reaction solvent due to the solubility of raw materials, etc., after synthesizing with a low boiling solvent, It may be replaced.

  Although there is no restriction | limiting in particular about the order which performs preparation of a raw material, Usually, after preparing compound (B), (C) and (D) first and making it melt | dissolve in a solvent, 20-150 degreeC, Preferably it is 60-120. The compound (A) is added dropwise at 0 ° C., and then reacted at 30 to 160 ° C., preferably 50 to 130 ° C.

  The charge molar ratio of the raw materials is adjusted according to the molecular weight and acid value of the target polyurethane. When the monohydroxy compound (E) is introduced into the polyurethane, the end of the polyretane molecule is an isocyanate group. It is necessary to use the compound (A) in excess of the compounds (B), (C), and (D) (so that the amount of isocyanate groups is more than the total amount of hydroxyl groups).

  Specifically, the charged molar ratio [compound (A): compound (B) + (C) + (D)] is 0.5 to 1.5: 1, preferably 0.8 to 1.2. : 1. Moreover, phosphorus containing diol compound (B): dihydroxy compound (D) is 1-9: 1, Preferably it is 2-8: 1.

  When the monohydroxy compound (E) is used, the number of moles of the diisocyanate compound (A) is made larger than the number of moles of [phosphorus-containing diol compound (B) + diol compound (C) + dihydroxy compound (D)] It is desirable to use the monohydroxy compound (E) in an amount of 0.5 to 1.5 times, preferably 0.8 to 1.2 times the molar amount of the excess moles of isocyanate groups. The excess number of moles of the isocyanate group refers to the number of moles obtained by subtracting the total number of moles of the compounds (B) and (D) from the number of moles of the compound (A).

  When the monoisocyanate compound (F) is used, the number of moles of [phosphorus-containing diol (B) + diol compound (C) + dihydroxy compound (D)] is set to be larger than the number of moles of the diisocyanate compound (A). It is desirable to use the monoisocyanate compound (F) in an amount of 0.5 to 1.5 times, preferably 0.8 to 1.2 times, the molar amount of the hydroxyl group. The excess number of moles of the hydroxyl group means the number of moles obtained by subtracting the number of moles of the compound (A) from the total number of moles of the compounds (B), (C) and (D).

  In order to introduce the monohydroxy compound (E) into the polyurethane, the polyurethane-containing diol (B), the diol compound (C), and the dihydroxy compound (D) and the diisocyanate (A) are almost completely reacted with the polyurethane. In order to react the isocyanate group remaining at both ends of the monohydroxy compound (E) with the monohydroxy compound (E), the monohydroxy compound (E) is dropped into the polyurethane solution at 20 to 150 ° C., more preferably at 70 to 120 ° C. Then, the reaction is completed by holding at the same temperature.

  In order to introduce the monoisocyanate compound (F) into the polyurethane, when the reaction between the phosphorus-containing diol (B), the diol compound (C) and the dihydroxy compound (D) and the diisocyanate (A) is almost completed, In order to react the hydroxyl group remaining at both ends of the polyurethane with the monoisocyanate compound (F), the monoisocyanate compound (F) is dropped into the polyurethane solution at 20 to 150 ° C, more preferably at 50 to 120 ° C. Then, the reaction is completed by holding at the same temperature.

[Thermosetting polyurethane resin composition]
The thermosetting polyurethane resin composition of the present invention contains the carboxyl group-containing polyurethane of the present invention and a solvent, and the carboxyl group-containing polyurethane is dissolved in the solvent. As this solvent, an organic solvent similar to the reaction solvent described above can be preferably used.

The carboxyl group-containing polyurethane concentration (solid content concentration) in the thermosetting polyurethane resin composition is preferably 10 to 90% by mass, more preferably 30 to 80% by mass.
In order to cure the thermosetting polyurethane resin composition of the present invention, other thermosetting resins such as an epoxy resin, a curing catalyst, an antifoaming agent and the like are further blended as necessary for the solder resist ink or overcoat. It can be carried out by preparing an ink, applying it by screen printing or the like and then drying and heating.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, o-cresol novolac type epoxy resin, biphenyl type epoxy resin, polyfunctional epoxy resin, amine type epoxy resin, complex Examples thereof include ring-containing epoxy resins, alicyclic epoxy resins, epoxidized polybutadiene, and silicone-containing epoxy resins. These may be used alone or in combination of two or more.

As a commercial item of the said bisphenol A type epoxy resin, Japan Epoxy Resin Co., Ltd. product "Epicoat 828,834,1002,1004" etc. are mentioned, for example.
Examples of commercially available products of the bisphenol F type epoxy resin include “Epicoat 806, 807, 4005P” manufactured by Japan Epoxy Resin Co., Ltd., “YDF-170” manufactured by Tohto Kasei Co., Ltd., and the like.

  Examples of commercially available phenol novolac epoxy resins include “Epicoat 152, 154” manufactured by Japan Epoxy Resin Co., Ltd. and “EPPN-201” manufactured by Nippon Kayaku Co., Ltd.

As a commercial item of the said o-cresol novolak-type epoxy resin, Nippon Kayaku Co., Ltd. "EOCN-125S, 103S, 104S" etc. are mentioned, for example.
As a commercial item of the said biphenyl type epoxy resin, "Epicoat YX-4000, YL-6640" by Japan Epoxy Resin Co., Ltd. etc. are mentioned, for example.

  Examples of commercially available products of the above polyfunctional epoxy resin include “Epicoat 1031S” manufactured by Japan Epoxy Resin Co., Ltd., “Araldite 0163” manufactured by Ciba Specialty Chemicals Co., Ltd., and “Denacol EX-611” manufactured by Nagase Kasei Co., Ltd. , EX-614, EX-614B, EX-622, EX-512, EX-521, EX-421, E-411, EX-321 "and the like.

  Examples of commercially available amine type epoxy resins include “Epicoat 604” manufactured by Japan Epoxy Resin Co., Ltd., “YH-434” manufactured by Tohto Kasei Co., Ltd., “TETRAD-X, TETRAD manufactured by Mitsubishi Gas Chemical Co., Ltd. -C ", Nippon Kayaku Co., Ltd." GAN ", Sumitomo Chemical Co., Ltd." ELM-120 ", etc. are mentioned.

As a commercial item of the said heterocyclic containing epoxy resin, "Araldite PT810" by Ciba Specialty Chemicals Co., Ltd. etc. are mentioned, for example.
Examples of commercially available products of the above alicyclic epoxy resins include “EHPE3150, EHPE3150CE, Celoxide 2000, Celoxide 2021, Celoxide 2081, Epoxide PB3600 Epoxide GT401” manufactured by Daicel Chemical Industries, Ltd., “ERL4234, 4299, 4221” manufactured by UCC. 4206 "and the like.

As a commercial item of the said epoxidized polybutadiene, Daicel Chemical Industries Co., Ltd. "Epolide PB3600" etc. are mentioned, for example.
Examples of commercially available silicone-containing epoxy resins include “KF-105, X-22-163A, X-22-163B, X-22-163C, X-22-169AS, X” manufactured by Shin-Etsu Chemical Co., Ltd. -22-169B ".

As a commercial item of the said phosphorus containing epoxy resin, Toto Kasei Co., Ltd. product "FX-305EK70" etc. are mentioned, for example.
Among these epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, biphenyl type epoxy resins, and alicyclic epoxy resins are preferable in terms of mechanical properties, adhesion, and bending resistance. The epoxy equivalent of the epoxy resin is 120 to 20,000, preferably 150 to 2,000.

  The epoxy resin is used in an amount of 1 to 100 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of the carboxyl group-containing polyurethane of the present invention. When the amount of the epoxy resin is less than the above range, the heat resistance, adhesion and bending resistance of the cured product of the present invention may be reduced. On the other hand, when the above range is exceeded, the low warpage of the cured product of the present invention may be reduced. And mechanical strength may decrease.

  In addition, the epoxy resin has an epoxy value of 0.2 to 2 equivalents, more preferably 0.5 to 1.5 equivalents relative to the acid value of the carboxyl group-containing polyurethane of the present invention. It is preferable to use it in an amount. If the amount is less than 0.2 equivalent, the curability of the cured product of the present invention may be reduced. If the amount is more than 2 equivalents, the storage stability of the resin composition of the present invention containing the epoxy resin may be decreased. is there.

The cured product of the present invention obtained as described above is excellent in flame retardancy, adhesion to a substrate, low warpage, flexibility, tackiness, plating resistance, solder heat resistance, and long-term reliability. Yes.
[Example]
EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited to these Examples.

[Example 1]
In a reaction vessel equipped with a stirrer, thermometer and condenser,
As the phosphorus-containing diol, 137.3 g of “FC-450” (hydroxyl value 454) manufactured by Asahi Denka Kogyo Co., Ltd.
28.69 g of 2,2-dimethylolpropanoic acid (manufactured by Nippon Kasei Co., Ltd.) as a carboxyl group-containing dihydroxy compound,
256.1 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Corporation) as a solvent
And heated to 70 ° C. to dissolve all the solid raw materials to obtain a solution. To this solution, 134.0 g of "T-80" (80:20 mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate) manufactured by Mitsui Takeda Chemical Co., Ltd. was added as a polyisocyanate using a dropping funnel. It was added dropwise over 10 minutes. After completion of the dropping, the reaction was carried out at 70 ° C. for 1 hour, then at 80 ° C. for 1 hour, then at 90 ° C. for 1 hour, and then at 100 ° C. for 1.5 hours. After confirming that the isocyanate had almost disappeared, isobutanol ( 3.0 g of Wako Pure Chemical Industries, Ltd.) was added dropwise, and the reaction was further performed at 100 ° C. for 2 hours. The number average molecular weight of the obtained carboxyl group-containing polyurethane was 5,410, and the acid value of the solid content was 39.8 mg-KOH.
/ G.

[Example 2]
In a reaction vessel equipped with a stirrer, thermometer and condenser,
As the phosphorus-containing diol, 45.17 g “FC-450” (hydroxyl value 454) manufactured by Asahi Denka Kogyo Co., Ltd.
10.56 g of 2,2-dimethylolbutanoic acid (manufactured by Nippon Kasei Co., Ltd.) as a carboxyl group-containing dihydroxy compound,
92.3 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Corporation) as a solvent
And heated to 70 ° C. to dissolve all the solid raw materials to obtain a solution. Thereafter, 44.27 g of “T-100” (2,4-tolylene diisocyanate) manufactured by Mitsui Takeda Chemical Co., Ltd. was added as a polyisocyanate to this solution, and then at 70 ° C. for 1 hour, then at 80 ° C. for 1 hour, The reaction was carried out at 90 ° C. for 1 hour and then at 100 ° C. for 1.5 hours, and after confirming that the isocyanate had almost disappeared, 1.0 g of isobutanol (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise. For 2 hours. The number average molecular weight of the obtained carboxyl group-containing polyurethane was 5,820, and the acid value of the solid content was 40.0 mg-KOH / g.

Example 3
In a reaction vessel equipped with a stirrer, thermometer and condenser,
As the phosphorus-containing diol, “FC-450” (hydroxyl value 454) 85,79 g manufactured by Asahi Denka Kogyo Co., Ltd.
21,13 g of 2,2-dimethylolbutanoic acid (manufactured by Nippon Kasei Co., Ltd.) as a carboxyl group-containing dihydroxy compound,
200.0 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Corporation) as a solvent
And heated to 100 ° C. to dissolve all the solid raw materials to obtain a solution. To this solution, 93.08 g of “Takenate 600” (1,3-bis (isocyanatomethyl) cyclohexane) manufactured by Mitsui Takeda Chemical Co., Ltd. was dropped as a polyisocyanate over 10 minutes with a dropping funnel. After completion of dropping, the reaction was carried out at 110 ° C. for 7 hours. After confirming that the isocyanate had almost disappeared, 2.0 g of isobutanol (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise, and the reaction was further carried out at 120 ° C. for 2 hours. Went. The number average molecular weight of the obtained carboxyl group-containing polyurethane was 3,420, and the acid value of the solid content was 39.6 mg-KOH / g.

Example 4
In a reaction vessel equipped with a stirrer, thermometer and condenser,
As the phosphorus-containing diol, “FC-450” (hydroxyl value 454) 87,47 g manufactured by Asahi Denka Kogyo Co., Ltd.
21,13 g of 2,2-dimethylolbutanoic acid (manufactured by Nippon Kasei Co., Ltd.) as a carboxyl group-containing dihydroxy compound,
200.0 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Corporation) as a solvent
And heated to 100 ° C. to dissolve all the solid raw materials to obtain a solution. To this solution, 91.40 g of “Takenate 500” (1,3-bis (isocyanatomethyl) benzene) manufactured by Mitsui Takeda Chemical Co., Ltd. was dropped as a polyisocyanate over 10 minutes with a dropping funnel. After completion of dropping, the reaction was carried out at 110 ° C. for 7 hours. After confirming that the isocyanate had almost disappeared, 2.0 g of isobutanol (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise, and the reaction was further carried out at 120 ° C. for 2 hours. Went. The number average molecular weight of the obtained carboxyl group-containing polyurethane was 3,860, and the acid value of the solid content was 39.8 mg-KOH / g.

Example 5
In a reaction vessel equipped with a stirrer, thermometer and condenser,
As the phosphorus-containing diol, 35.56 g of “FC-450” (hydroxyl value 454) manufactured by Asahi Denka Kogyo Co., Ltd.
10.56 g of 2,2-dimethylolbutanoic acid (manufactured by Nippon Kasei Co., Ltd.) as a carboxyl group-containing dihydroxy compound,
92.3 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Corporation) as a solvent
And heated to 70 ° C. to dissolve all the solid raw materials to obtain a solution. Thereafter, 53.88 g of “MDI” manufactured by Meisei Chemical Co., Ltd. (80:20 mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate) was added to this solution as a polyisocyanate at 70 ° C. 1 hour, 1 hour at 80 ° C., 1 hour at 90 ° C., 1.5 hours at 100 ° C. After confirming that the isocyanate almost disappeared, isobutanol (manufactured by Wako Pure Chemical Industries, Ltd.) 0 g was added dropwise, and the reaction was further performed at 100 ° C. for 2 hours. The number average molecular weight of the obtained carboxyl group-containing polyurethane was 6,380, and the acid value of the solid content was 40.2 mg-KOH / g.

Example 6
In a reaction vessel equipped with a stirrer, thermometer and condenser,
As the phosphorus-containing diol, 34.30 g of “FC-450” (hydroxyl value 454) manufactured by Asahi Denka Kogyo Co., Ltd.
10.56 g of 2,2-dimethylolbutanoic acid (manufactured by Nippon Kasei Co., Ltd.) as a carboxyl group-containing dihydroxy compound,
100 g of γ-butyrolactone (Mitsubishi Chemical Corporation) as a solvent
And heated to 100 ° C. to dissolve all the solid raw materials to obtain a solution. To this solution, 55.14 g of “Desmodur W” (1,3-bis (isocyanatomethyl) benzene) manufactured by Mitsui Takeda Chemical Co., Ltd. was dropped as a polyisocyanate with a dropping funnel over 10 minutes. After completion of the dropwise addition, the reaction was carried out at 110 ° C. for 5 hours. After confirming that the isocyanate had almost disappeared, 2.0 g of isobutanol (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise, and the reaction was further carried out at 120 ° C. for 2 hours. Went. The number average molecular weight of the obtained carboxyl group-containing polyurethane was 3,320, and the acid value of the solid content was 39.8 mg-KOH / g.

[Comparative Example 1]
In a reaction vessel equipped with a stirrer, thermometer and condenser,
"T-4691" manufactured by Asahi Kasei Corporation (copolymerized polycarbonate diol having a molar ratio of 1,4-butanediol and 1,6-hexanediol of 90:10) 230.7 g,
2,2-dimethylolbutanoic acid (manufactured by Nippon Kasei Co., Ltd.) 37.0 g as a carboxyl group-containing dihydroxyl compound,
346.9 g of diethylene glycol ethyl ether acetate (manufactured by Daicel Chemical Industries) as a solvent
And heated to 70 ° C. to dissolve all the solid raw materials to obtain a solution. To this solution, 82.8 g of “T-80” (80:20 mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate) manufactured by Mitsui Takeda Chemical Co., Ltd. was added as a polyisocyanate using a dropping funnel. It was added dropwise over 10 minutes. After completion of the dropping, the reaction was carried out at 70 ° C. for 1 hour, 80 ° C. for 1 hour, 90 ° C. for 1 hour, and 100 ° C. for 1 hour. After confirming that the isocyanate almost disappeared, Isobutanol (Wako Pure Chemical Industries, Ltd.) ) 3 g was added dropwise, and the reaction was further carried out at 100 ° C. for 1 hour. The number average molecular weight of the obtained carboxyl group-containing polyurethane was 13,500, and the acid value of the solid content was 40.0 mg-KOH / g.

[Evaluation]
First, using the carboxyl group-containing polyurethane obtained in the above Examples and Comparative Examples, a solder resist ink was prepared as follows. Subsequently, the flame retardancy of the cured product obtained by curing the obtained solder resist ink was evaluated as follows. The evaluation results are shown in Table 1.

<Preparation of solder resist ink>
Using the polyurethane solution obtained in Example 1 (solid content concentration of 54% by mass) as the thermosetting polyurethane resin composition, an amount of 1.1 equivalent of the epoxy group to the carboxyl group of the polyurethane is added to this solution. Of epoxy resin (“Epicoat 834” manufactured by Japan Epoxy Resin Co., Ltd.), and 1 mass% of melamine as a curing catalyst and Big Chemie Japan (as an antifoaming agent) with respect to 100 mass% of the polyurethane solid content. "TSA-750S" manufactured by Co., Ltd. was blended at a ratio of 0.75 mass%. Next, a solder resist ink was prepared by kneading the composition containing these components three times through a three-roll mill (manufactured by Kodaira Seisakusho, model: RIII-1RM-2).
Solder resist inks were similarly prepared from the polyurethane solutions (thermosetting polyurethane resin compositions) obtained in Examples 2 to 6 and Comparative Example 1.

<Flammability>
The obtained solder resist ink is a # 200 mesh polyester plate, 25 μm thick polyimide film (Kapton (registered trademark) 100H, manufactured by Toray DuPont Co., Ltd.), 38 μm thick polyimide film (Kapton (registered trademark) 150EN, Toray DuPont Co., Ltd.] and 75 μm thick polyimide film [Kapton (registered trademark) 300H, Toray DuPont (
Applied to each surface by screen printing. 80 ° C after printing
For 30 minutes, followed by thermosetting at 120 ° C. for 1 hour. After heat curing, the other surface was coated with ink by screen printing and cured at 120 ° C. for 30 minutes and further at 150 ° C. for 2 hours. The obtained cured film was tested for flame retardancy in accordance with UL-94 standards.

(Evaluation criteria)
○: Does not burn or extinguishes immediately even if it catches fire.
X: Burn.

Claims (19)

A carboxyl group-containing polyurethane having a structure derived from a phosphorus-containing diol compound (B) having a hydroxyl value of 200 to 500 mg-KOH / g. The carboxyl group-containing polyurethane according to claim 1, wherein the phosphorus-containing diol compound (B) is a compound represented by the following general formula (1);

[In the formula (1), each R ₁ independently represents an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms or an arylalkyl group, and The carbon-carbon bond contained in the group may be replaced with an ether bond or an ester bond, and the hydrogen atom contained in these groups may be replaced with a hydroxyl group.
Each R ₂ independently represents a methylene group or an alkylene group having 2 to 18 carbon atoms;
The carbon-carbon bond contained in these groups may be replaced with an ether bond or an ester bond, and the hydrogen atom contained in these groups may be replaced with a hydroxyl group. ]
. (A) a polyisocyanate compound,
The carboxyl group according to claim 1 or 2, which is obtained by reacting (B) a phosphorus-containing diol compound having a hydroxyl value of 200 to 500 mg-KOH / g and (D) a carboxyl group-containing dihydroxy compound. Group-containing polyurethane.   Along with the polyisocyanate compound (A), the phosphorus-containing diol compound (B) and the dihydroxy compound (D), (C) a diol compound [however, the diol compound (B) and the dihydroxy compound (D) are excluded. The carboxyl group-containing polyurethane according to claim 3, which is obtained by reacting at least one of (E) a monohydroxy compound and (F) a monoisocyanate compound.   More than 10 mol% of the polyisocyanate compound (A) (the total amount of the compound (A) is 100 mol%) is an isocyanate group having 6 to 30 carbon atoms (excluding the number of carbon atoms in the isocyanate group). The carboxyl group-containing polyurethane according to claim 3, which is a containing aromatic compound and / or an isocyanate group-containing alicyclic compound.   The diol compound (C) is at least one compound selected from the group consisting of a diol compound having 2 to 18 carbon atoms, a polyether diol, a polyester diol, and a polycarbonate diol. Carboxyl group-containing polyurethane. The carboxyl group-containing polyurethane according to claim 3, wherein the dihydroxy compound (D) is 2,2-dimethylolpropionic acid or 2,2-dimethylolbutanoic acid.   The monohydroxy compound (E) is at least one selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol and t-butanol, glycolic acid and hydroxypivalic acid. 5. The carboxyl group-containing polyurethane according to claim 4, which is a compound.   The monoisocyanate compound (F) is a phenyl isocyanate, hexyl isocyanate, dodecyl isocyanate, and diisocyanate compound methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, amyl alcohol The carboxyl group-containing polyurethane according to claim 4, which is at least one compound selected from the group consisting of mono-adducts of hexyl alcohol or octyl alcohol.   The phosphorus-containing diol compound (B) is used in an amount in the range of 20 to 95 mol% with respect to 100 mol% of the total amount of the compounds (B) and (D). Carboxyl group-containing polyurethane.   The phosphorus-containing diol compound (B) is used in an amount in the range of 20 to 95 mol% with respect to 100 mol% of the total amount of the compounds (B), (C) and (D). 4. The carboxyl group-containing polyurethane according to 4. The number average molecular weight is 1,000 to 100,000, and the acid value is 5 to 120 mg-K.
It is OH / g, The carboxyl group-containing polyurethane in any one of Claims 1-11 characterized by the above-mentioned. The number average molecular weight is 3,000 to 50,000, and the acid value is 10 to 70 mg-KO.
It is H / g, The carboxyl group-containing polyurethane in any one of Claims 1-12 characterized by the above-mentioned.   A heat curing comprising the carboxyl group-containing polyurethane according to any one of claims 1 to 13 and a solvent having a boiling point of 120 ° C or more, wherein the carboxyl group-containing polyurethane is dissolved in the solvent. -Based polyurethane resin composition.   The solvent is toluene, xylene, ethylbenzene, nitrobenzene, isophorone, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, dipropylene glycol methyl. Ether acetate, dipropylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol methyl ether acetate, methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, ethyl ethoxypropionate, n-butyl acetate, isoamyl acetate, lactic acid Chill, cyclohexanone, .gamma.-butyrolactone and thermosetting polyurethane resin composition according to claim 14, wherein the at least one selected from the group consisting of dimethyl sulfoxide.   The thermosetting polyurethane resin composition according to claim 14 or 15, wherein the solid content concentration is 30 to 80% by mass. A solder resist ink comprising the thermosetting polyurethane resin composition according to any one of claims 14 to 16 and an epoxy resin.   An ink for overcoat comprising the thermosetting polyurethane resin composition according to any one of claims 14 to 16 and an epoxy resin.   A cured product obtained by curing the solder resist ink according to claim 17 or the overcoat ink according to claim 18.