JP2001002769A - Phosphorus-containing unsaturated polyester resin and resin composition containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject resin having high flame retardance and excellent in heat resistance, moisture resistance, mechanical properties, productivity, or the like, in spite of being a halogen-free resin by using a specific phosphorus- containing polycarboxylic acid in the production of an unsaturated polyester resin. SOLUTION: This resin having 0.2-10 wt.% phosphorus content is produced by using a phosphorus-containing polycarboxylic acid of formula I, formula II or formula III (R1 to R6 are each a carboxyl-containing 2-20C acyl) as a part or the whole of an acid component to be used in the production of an unsaturated polyester resin. The phosphorus-containing polycarboxylic acid is obtained by reacting a phosphorus-containing diol of formula IV, or the like, [e.g. 10-(2',5'-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- oxide] with a polycarboxylic acid anhydride (e.g. maleic anhydride).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a halogen-free resin composition having excellent flame retardancy and a cured product thereof. More specifically, it contains an unsaturated polyester resin obtained by using a phosphorus-containing polycarboxylic acid represented by the molecular formula (1), (2) or (3) for part or all of an acid component, and has a high flame retardancy. The present invention relates to a halogen-free unsaturated polyester resin composition excellent in heat resistance, moisture resistance, mechanical properties, productivity, etc., as well as its properties, and a cured product thereof.

[0002]

2. Description of the Related Art Thermosetting resins having unsaturated bonds, such as unsaturated polyester resins and vinyl ester resins, have been widely used in various industrial fields in recent years because of their excellent heat resistance, mechanical properties, electrical properties and the like. I have. Conventionally, the flame retardation of these resins has been achieved by a method such as using a halogen-based flame retardant or introducing a halogen element into the resin skeleton. However, in recent years, with increasing interest in environmental pollution, it has become difficult to use a resin using a halogen or a cured product thereof as a source of dioxin during combustion. Therefore, flame retardation using elements such as phosphorus and antimony instead of halogen is being studied. However, since resins such as the above-mentioned unsaturated polyesters are used together with reactive diluents such as styrene and methyl methacrylate, which are usually difficult to make flame retardant, a large amount of flame retardant is used to make the part flame-retardant. Need to be added. Moreover, since these flame retardants are not usually incorporated into the crosslinked structure of the resin, if added in large amounts, the mechanical properties of the cured product will be reduced. Furthermore, many phosphorus-based flame retardants have a phosphate ester structure, but the phosphate ester structure is inherently high in hygroscopicity and low in heat resistance, which lowers the moisture resistance and heat resistance of the cured product. Might be. Conventionally, a method of introducing phosphorus into a resin skeleton using a reactive phosphorus-based flame retardant is also known, but this method increases the phosphorus content, so that the cured product becomes brittle, and satisfactory products are obtained. Not obtained. Therefore, in a laminated board for electronic and electrical materials that require particularly severe flame retardancy, heat having an unsaturated bond that provides a cured product excellent in heat resistance, moisture resistance, mechanical properties and productivity, while being halogen-free. There was no curable resin or composition.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cured product which is halogen-free, has high flame retardancy, and has various properties such as good heat resistance, moisture resistance, mechanical properties, and productivity. Development of a resin composition that gives

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, the following formula (1) is obtained.
It has been found that the phosphorus-containing polycarboxylic acid represented by (2) or (3) is less likely to decrease in moisture resistance and can maintain high heat resistance as compared with conventionally known phosphate compounds. In particular, the phosphorus-containing polycarboxylic acid represented by the formula (1), (2) or (3) is converted to a compound represented by the formula (4) or (5)
Alternatively, when introduced into the skeleton of an unsaturated polyester resin by a method of adding a polycarboxylic anhydride such as maleic anhydride or itaconic anhydride to the phosphorus-containing diol represented by (6), the cured product is subjected to a pressure cooker test. In addition to obtaining very good results in severe high-temperature and humidity resistance tests such as (PCT), we obtained the knowledge that flame retardancy can be achieved with a lower phosphorus content than before despite being halogen-free. Thus, the present invention has been completed. That is, the present invention provides (1) the following formula (1), (2) or (3) as a part or all of an acid component used for producing an unsaturated polyester resin:

Embedded image (Wherein, R ^{1 to} R ⁶ are the same or different and represent an acyl group having a carboxyl group and having 2 to 20 carbon atoms.) A phosphorus content produced using a phosphorus-containing polycarboxylic acid represented by the formula: Phosphorus content comprising 0.2 to 10% by weight of a phosphorus-containing unsaturated polyester resin, (2) a phosphorus-containing unsaturated polyester resin as described in (1) above, and a reactive diluent having a C ＝ C double bond. The unsaturated unsaturated polyester resin composition according to the above (2), further comprising 0.1 to 7% by weight of a phosphorus-containing unsaturated polyester resin composition, and (3) a rubber component of 1 to 30% by weight based on 100% by weight of the phosphorus-containing polyester resin. A polyester resin composition, (4) a curing agent of 0.1 to 5% by weight based on 100% by weight of the unsaturated polyester resin composition,
The unsaturated polyester resin composition according to the above (2), which contains 0 to 400% by weight of a filler, and (5) a fiber reinforcing material impregnated with the unsaturated polyester resin composition according to the above (4), are laminated. , A copper foil-clad laminate integrally cured with copper foil,
(6) The following formula (4), (5) or (6):

Embedded image A method for producing a phosphorus-containing polycarboxylic acid represented by the formula (1), (2) or (3), wherein at least one kind of polycarboxylic anhydride is reacted with the phosphorus-containing diol represented by
(7) The method for producing a phosphorus-containing dicarboxylic acid according to the above (6), wherein the polycarboxylic anhydride is at least one of maleic anhydride, itaconic anhydride and succinic anhydride, and (8) formulas (4) and (4). 5) A method for producing a phosphorus-containing unsaturated polyester resin, which comprises reacting at least one polycarboxylic anhydride with the phosphorus-containing diol represented by (6) and reacting the resulting reaction mixture with a polyhydric alcohol. .

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the above formulas (1), (2) and (3), R ^{1 to} R ⁶ are the same or different and have 2 to 20 carbon atoms having a carboxyl group (including carbon atoms of a carboxyl group). ) Is an acyl group. The number of carboxyl groups in R ^{1 to} R ⁶ is one or more, but usually one. Examples of the acyl group having a carboxyl group represented by R ^{1 to} R ⁶ include a saturated aliphatic group, an alicyclic group, an aromatic group, an araliphatic group, and an unsaturated aliphatic group. Or an acyl group containing more than that. As the saturated aliphatic group, a linear or branched saturated aliphatic group is used, as the alicyclic group, a 5- or 6-membered ring group is used, and as the aromatic group, a group having a benzene ring or a naphthalene ring is used. Examples of the aliphatic group include an aromatic group having a saturated or unsaturated aliphatic group as a substituent, and examples of the unsaturated aliphatic group include an aliphatic group having one or more C ＝ C double bonds. The unsaturated polyester resin of the present invention was produced using a phosphorus-containing polycarboxylic acid represented by the formula (1), (2) or (3) as a part or all of an acid component used for the production. It is an unsaturated polyester resin. The phosphorus-containing polycarboxylic acid represented by the formula (1), (2) or (3) can be obtained by reacting a compound represented by the formula (4), (5) or (6)
And at least one polycarboxylic anhydride is added to the phosphorus-containing diol represented by Examples of the polycarboxylic anhydride to be added to the phosphorus-containing diol of the formula (4), (5) or (6) include unsaturated polycarboxylic anhydrides such as maleic anhydride and itaconic anhydride, for example, succinic anhydride, Adipic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, trimellitic anhydride, and saturated polycarboxylic anhydrides such as pyromellitic anhydride,
Among them, maleic anhydride, itaconic anhydride and succinic anhydride are preferred. These may be used alone or as a mixture of two or more.

The reaction of the phosphorus-containing diols of the formulas (4), (5) or (6) with these polycarboxylic anhydrides can be carried out in one mole of the phosphorus-containing diols of the formulas (4), (5) or (6). On the other hand, the polycarboxylic anhydride is preferably reacted in the range of 2 to 10 mol, and more preferably 2.1 to 8 mol. Japanese Patent Application Laid-Open No. 61-118393 discloses a technique for isolating the obtained product by using acetic acid or the like as a solvent. However, since acetic acid or the like is not a constituent component of the resin, it is removed from the system after the reaction. This method is inferior in productivity because it is necessary to carry out an operation for isolating the reaction product. In the present invention, by appropriately selecting an acid anhydride and adjusting and using an excess amount thereof, it is possible to perform the next reaction without using another solvent, and perform an operation for isolating the reaction product. Since it can be manufactured continuously without using the same, the productivity is remarkably excellent. In order to carry out such a reaction efficiently, a catalyst can be used. Examples of the catalyst include catalysts usually used as an esterification catalyst, such as zinc acetate, dibutyltin maleate, and titanium tetrabutoxide.

Examples of the dihydric alcohol, that is, diols, include alkanediol, oxaalkanediol, and diol obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide to bisphenol A. In addition, it is also possible to use monohydric or trihydric alcohols. Examples of alkanediols include, for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol,
1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol,
Examples include 1,6-hexanediol and cyclohexanediol. Examples of the oxaalkanediol include diethylene glycol and triethylene glycol. Examples of the monohydric or trihydric alcohol used in combination with these glycols include octyl alcohol, oleyl alcohol, and trimethylolpropane.

The synthesis of the unsaturated polyester resin is generally carried out under heating, and the reaction proceeds while removing by-produced water. In general, the glass transition temperature (Tg) of the unsaturated polyester resin is adjusted by lowering the crosslink density and reactivity of the resin by selecting the raw materials, as a saturated acid such as adipic acid and sebacic acid, and as a diol such as diethylene glycol and diethylene glycol. By using a raw material having a long-chain molecular structure such as propylene glycol, the glass transition temperature can be lowered, and conversely, the crosslink density and reactivity of the resin can be increased, and rigid materials such as hydrogenated bisphenol A can be used as the raw material. By using a diol having a specific structure, the glass transition temperature can be increased. In order to make the resin exhibit flame retardancy, the content of phosphorus contained in the unsaturated polyester resin is preferably from 0.2 to 10.0% by weight, but in particular, electronic or electric parts requiring severe flame retardancy. It is more preferable that the amount be 1.0 to 8.0% by weight for the use of the laminated board for use. At lower phosphorus contents, it is difficult to develop flame retardancy, and at higher phosphorus contents, high flame retardancy can be developed, but heat resistance, moisture resistance, mechanical properties, and compatibility tend to decrease. Eventually, productivity will be reduced. In order to obtain high heat resistance, moisture resistance and mechanical properties, the unsaturated polyester resin
While having a double bond equivalent of from 1,000 to 1,000 g / mol, the obtained resin is diluted with a reactive diluent having a C ＝ C double bond.
g is preferred. If the double bond equivalent is less than this value, the crosslink density will be high and the cured product will be brittle, which may hinder actual use. On the other hand, if the double bond equivalent exceeds this value, the crosslinking density becomes insufficient, and as a result, it becomes difficult to obtain sufficiently high Tg and other physical properties.

The obtained resin has at least one double bond (C = C bond) in the molecule for the purpose of lowering the viscosity.
It is preferable to dilute with a reactive diluent having As a reactive diluent, acrylic acid, unsaturated fatty acids such as methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate,
Unsaturated carboxylic acid esters such as 2-ethylhexyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, (Meta)
Nitrogen-based monomers such as acrylamide and (meth) acrylonitrile; aromatic vinyl compounds such as styrene, vinyltoluene, divinylbenzene and pt-butylstyrene;
Ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol Examples thereof include polyfunctional (meth) acrylates such as triacrylate and pentaerythritol tetraacrylate, and these can be used alone or in combination. Of these, styrene is particularly preferably used.

The content of the reactive diluent is usually in the range of 10 to 80% by weight of the total 100% by weight of the resin composition. However, in order to exhibit higher flame retardancy, the phosphorus content in the resin composition is preferably set to 0.1 to 7% by weight. For this purpose, the content of reactive diluent is 10 to 10.
It is preferably in the range of 60% by weight, particularly preferably in the range of 10 to 45% by weight. The resin of the present invention is, for the purpose of improving physical properties and productivity, a vinyl ester resin conventionally well known as a resin having an unsaturated bond,
It can be used by mixing with an unsaturated polyester resin or the like. These amounts are appropriately determined depending on the required performance. However, from the viewpoint of flame retardancy, it is preferable that the flame retardant resin 10 is used.
5 to 200% by weight, more preferably 10% to 0% by weight
１５０150% by weight. In order to impart toughness, impact resistance, punching workability, interlayer adhesion, and the like, a rubber component can be added to the resin composition of the present invention. As the rubber component to be added, liquid rubber such as carboxyl group terminal NBR, epoxy group terminal NBR, vinyl terminal NBR,
Alternatively, modified rubbers thereof, fine particle rubber such as crosslinked acrylic fine particles and the like can be mentioned. The amount of the rubber component used is usually 1 to 30% by weight based on 100% by weight of the resin composition.

For the purpose of imparting even higher flame retardancy to the resin composition of the present invention, a flame retardant not using halogen, such as a phosphorus-based or silicone-based compound, may be added in such an amount that the physical properties are not adversely affected. The flame-retardant resin composition of the present invention can be easily cured by adding a usual unsaturated polyester resin, a curing agent used for curing a vinyl ester resin and a curing accelerator if necessary. . Examples of the curing agent used in the present invention include organic peroxides such as methyl ethyl ketone peroxide, t-butyl peroxybenzoate, benzoyl peroxide, dicumyl peroxide, and cumene hydroperoxide. The amount of the curing agent used is the resin composition 10
The amount is preferably from 0.1 to 5% by weight, more preferably from 0.5 to 3% by weight, based on 0% by weight. Examples of the curing accelerator include cobalt naphthenate, cobalt octoate, dimethylaniline, diethylaniline, and acetylacetone. The amount of the curing accelerator used is 100
0.01 to 3% by weight with respect to% by weight is preferred. The resin composition of the present invention is conventionally used, a filler, a low-shrinking agent, a curing agent, a pigment, a dye, a polymerization inhibitor, a fiber reinforcing material, an internal mold release agent, a thickener and the like are blended. Various cured products can be obtained. Examples of the filler include aluminum hydroxide, glass powder, calcium carbonate, talc, silica, clay, glass balloon and the like. These are usually
It is used in an amount of 0 to 400% by weight based on 100% by weight of the resin composition.

As the low-shrinking agent, saturated polyester,
Polymethyl methacrylate, polyvinyl acetate, cross-linked polystyrene, styrene-butadiene (block) copolymer and hydrogenated product thereof, vinyl acetate-styrene (block) copolymer, (meth) acryl-styrene (block) copolymer, etc. Used. These low-shrinkage agents are usually used in an amount of 0 to 30% by weight based on 100% by weight of the resin composition. Examples of the internal release agent include metal soaps typified by calcium stearate and zinc stearate, silicon and fluorine-based organic compounds, and phosphoric acid-based compounds. Usually, it is used in an amount of 0 to 10% by weight. Examples of the pigment include titanium oxide, carbon black, red iron oxide, and phthalocyanine blue. Examples of the thickener include oxides and hydroxides such as magnesium and calcium. As the fiber reinforcing material used for the reinforcing fiber layer, generally, glass fibers having a diameter of about 8 to 15 μm and a length of 25 mm or less are used. The fiber reinforcing material is usually blended in an amount of about 1 to 40% by weight based on the total amount of the composition. In addition, the flame retardant resin of the present invention uses a part or all of the above-mentioned compounding agents, and after forming a resin composition, is impregnated into glass cloth, glass paper, or the like to form a reinforcing fiber layer, which is appropriately laminated. By curing, a laminate can be obtained. When a copper foil is applied and cured integrally when the reinforcing fiber layer is cured, a copper foil-clad laminate useful as an electronic or electric material can be obtained.

[0013]

The present invention will be described more specifically with reference to examples, comparative examples and test examples, but the present invention is not limited to these examples. Example 1 A 2-liter 5-necked flask equipped with a stirrer, a thermometer, a nitrogen gas inlet tube and a partial reflux condenser equipped with a thermometer at the top of a column was charged with 10- (2 ', 5'-dihydroxyphenyl) -9,
437 g of 10-dihydro-9-oxa-10 phosphaphenanthrene-10-oxide, itaconic anhydride 14
6 g, 225 g of succinic anhydride, 0.005 g of zinc acetate as a catalyst, and 0.1 g of hydroquinone as a polymerization inhibitor.
05 g was charged and reacted at 120 ° C. for 3 hours. Thereafter, 130 g of fumaric acid, 171 g of propylene glycol, and 120 g of dipropylene glycol were charged, and the inside of the reactor was replaced with nitrogen. Then, a dehydration condensation reaction was performed at 210 ° C. for 6 hours and a phosphorus-containing unsaturated polyester having an acid value of 26.9 mgKOH / g. 1102 g of resin was obtained (phosphorus content 3.7).
%). This unsaturated polyester resin was diluted with 735 g of a styrene monomer to obtain a resin composition (A).

Example 2 10- (2 ', 5'-dihydroxyphenyl) was placed in a 2-liter 5-neck flask equipped with a stirrer, thermometer, nitrogen gas inlet tube and a partial reflux condenser equipped with a thermometer at the top of the column. -9,
447 g of 10-dihydro-9-oxa-10 phosphaphenanthrene-10-oxide, maleic anhydride 11
3 g, succinic anhydride 230 g, zinc acetate 0.005 g as a catalyst, and hydroquinone 0.1 as a polymerization inhibitor.
05 g was charged and reacted at 120 ° C. for 3 hours. Thereafter, 133 g of fumaric acid, 175 g of propylene glycol and 98 g of diethylene glycol were charged, and the inside of the reactor was replaced with nitrogen. Then, a half-hour dehydration condensation reaction was performed at 210 ° C. for 6 hours, and 1069 g of a phosphorus-containing unsaturated polyester resin having an acid value of 28.9 mgKOH / g. (Phosphorus content 3.9%). The unsaturated polyester resin was diluted with 713 g of a styrene monomer to obtain a resin composition (B).

Example 3 417 g of diphenylphosphinyl hydroquinone was placed in a 2-liter 5-neck flask equipped with a stirrer, a thermometer, a nitrogen gas inlet tube and a partial reflux condenser equipped with a thermometer at the top of the column.
143 g of itaconic anhydride, 220 g of succinic anhydride, 0.005 g of zinc acetate as a catalyst, and 0.05 g of hydroquinone as a polymerization inhibitor were charged and reacted at 120 ° C. for 3 hours. Thereafter, 128 g of fumaric acid, 167 g of propylene glycol, and 118 g of dipropylene glycol were charged, and the inside of the reactor was replaced with nitrogen. Then, a dehydration condensation reaction was performed at 210 ° C. for 6 hours and a phosphorus-containing unsaturated acid having an acid value of 28.2 mgKOH / g. 1066 g of a polyester resin was obtained (phosphorus content: 3.8%). This unsaturated polyester resin was diluted with 710 g of a styrene monomer to obtain a resin composition (C).

Comparative Example 1 Newpol BP-23 (manufactured by Sanyo Chemical Co., Ltd.) was placed in a 2-liter 5-necked flask equipped with a stirrer, thermometer, nitrogen gas inlet tube and a partial reflux condenser equipped with a thermometer at the top of the column. , Bisphenol A propylene oxide adduct, molecular weight 35
6.0) 534.0 g, propylene glycol 285.
3 g, fumaric acid 580.4 g and hydroquinone 0.
After charging 05 g and replacing the inside of the reactor with nitrogen, 210 ° C.
Dehydration condensation reaction for 7 and a half hours with an acid value of 29.7 mg KO
H / g phosphorus-free unsaturated polyester resin 12
28 g were obtained. This unsaturated polyester resin was diluted with 819 g of a styrene monomer to obtain a resin composition (D).

Test Example 1 Next, the resins (A) to (D) obtained in Examples and Comparative Examples
And a resin and a filler are blended in the blending ratio shown in [Table 1] to prepare a casting plate having a thickness of 1 mm.
The heat resistance and the heat resistance after PCT were measured and evaluated. The results are shown in [Table 1]. Curing conditions: 100 ° C. × 60 minutes + 175 ° C. × 30 minutes. Flame retardancy: conforms to UL-94. Heat resistance: A casting plate is attached to a solder bath at 260 ° C., and the time until blistering is measured. Heat resistance after PCT: 1 under conditions of 121 ° C x 95% humidity
Perform a time pressure cooker test and then measure the above heat resistance. Glass transition temperature (Tg): A 3 mm-thick cast plate was separately prepared, dynamic viscoelasticity was measured, and determined from the peak temperature of tan δ.

[0018]

[Table 1] As is clear from Table 1, in the case of the resin composition of Comparative Example 1 in which a conventional phosphorus-based flame retardant was blended to make it flame-retardant, the required flame retardancy was barely obtained, but the required Is not obtained, and the moisture resistance after PCT is considerably reduced, which is problematic for industrial use. On the other hand, the resin compositions of Examples 1 to 3 of the present invention have solved all of these problems.

[0019]

The resin composition of the present invention is halogen-free and exhibits high flame retardancy at a low phosphorus content despite having a relatively large amount of a flammable reactive diluent. Moreover, a cured product having high heat resistance, moisture resistance and good mechanical properties is provided. Further, the production of the resin composition itself is easy, which is advantageous from the viewpoint of industrial productivity.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 67/06 C08L 67/06 C09K 21/12 C09K 21/12 21/14 21/14 (72) Inventor Hiroshi Takeuchi 2-17-85, Jusanhoncho 2-chome, Yodogawa-ku, Osaka-shi F-term in the chemical product company of Takeda Pharmaceutical Co., Ltd. 4F072 AA02 AA07 AB09 AD39 AE00 AE02 AE09 AE11 AE12 AE13 AF01 AF02 AF03 AF04 AF06 AF17 AG03 AG17 AG19 AH21 AK05 AK14 AL12 4H028 AA12 AA46 BA06 4J002 AC07X AC10X BG04X CF26W DE148 DE238 DJ018 DJ038 DJ048 DL008 EA046 EF046 EH076 EH106 EK027 EK037 EK047 EK057 EK077 EP016 ABER18FA018AB AB006 AB078 AB078 AC03 AC06 BA05 BA06 BA07 BA13 BA14 BA19 BA20 BA24 BA26 BA27 CA08 CA14 CA18 CA19 CA36 CB04 CD02 4J029 AA07 AB01 AC01 AE03 AE18 BA02 BA03 BA04 BA05 BA08 BA09 BA10 BF09 BF18 CB07B CC07 CE03 CF03 CF13 CF19 CH03 DC09 GA12 GA13 GA17 GA23 HB06 JA093 JA123 JA283 JA293 JA303 JB042 JB172 JB182 JB223 JC122 JC142 JE023 JE092 JF313 JF223

Claims (8)

[Claims] (1) As part or all of an acid component used for producing an unsaturated polyester resin, the following formulas (1) and (2)
Or (3): (Wherein, R ^{1 to} R ⁶ are the same or different and represent an acyl group having a carboxyl group and having 2 to 20 carbon atoms.) A phosphorus content produced using a phosphorus-containing polycarboxylic acid represented by the formula: 0.2 to 10% by weight of a phosphorus-containing unsaturated polyester resin. 2. A phosphorus-containing unsaturated polyester resin having a phosphorus content of 0.1 to 7% by weight, comprising the phosphorus-containing unsaturated polyester resin according to claim 1 and a reactive diluent having a C ＝ C double bond. Composition. 3. The unsaturated polyester resin composition according to claim 2, further comprising a rubber component in an amount of 1 to 30% by weight based on 100% by weight of the phosphorus-containing polyester resin. 4. An unsaturated polyester resin composition 10
0.1 to 5% by weight of curing agent for 0% by weight, 0 to 400
3. The unsaturated polyester resin composition according to claim 2, comprising a filler by weight. 5. A copper foil-clad laminate obtained by laminating a fiber reinforcing material impregnated with the unsaturated polyester resin composition according to claim 4 and integrally curing with a copper foil. 6. A compound represented by the following formula (4), (5) or (6): A method for producing a phosphorus-containing polycarboxylic acid represented by the above formula (1), (2) or (3), wherein at least one kind of polycarboxylic anhydride is reacted with a phosphorus-containing diol represented by the following formula: 7. The polycarboxylic anhydride is maleic anhydride,
The method for producing a phosphorus-containing dicarboxylic acid according to claim 6, which is at least one of itaconic anhydride and succinic anhydride. 8. A phosphorus compound comprising reacting at least one polycarboxylic anhydride with a phosphorus-containing diol represented by the formula (4), (5) or (6), and reacting a polyhydric alcohol with the obtained reaction mixture. Method for producing unsaturated polyester resin.