JPH0231090B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a curable resin composition, and more particularly to a useful curable resin composition that contains an unsaturated polyester as a main component and has reduced volumetric shrinkage during curing. Conventionally, there are various types of resin compositions that can be cured by light or heat to produce films and other resin molded products, and thermosetting resins and photocuring resins are widely used. Among them, the spread of photocurable photosensitive resins has been remarkable in recent years, especially liquid photosensitive resins.
Highly adaptable to various uses due to polymer design,
It contributes to improving the working environment and is used in a wide range of applications due to its economic efficiency, such as its fast curing speed. However, in reality, these cured products have poor moldability.
It did not satisfy all of the properties such as adhesion, chemical resistance, and physical properties. In particular, it is a well-known fact that volumetric shrinkage during curing causes poor adhesion (peeling), warping, molding distortion due to flow, etc., which often deteriorates the performance of the resulting cured product. It is known that unsaturated polyester resins, whether thermosetting or photocuring, generally experience a volumetric shrinkage of 7 to 12% during curing, which is considered one of their major drawbacks. This is thought to be caused by a decrease in free volume due to crosslinking reactions of polymer chains, and although many attempts have been made to solve this drawback, none have been found to be satisfactory. For example, an attempt was made to blend a long-chain saturated polymer as a polymeric binder (Japanese Patent Publication No. 7468/1983, etc.)
However, in reality, it is necessary to incorporate a considerable amount of a polymer compound in order to reduce the volumetric shrinkage during curing, and there are many problems such as compatibility with the crosslinking monomer and viscosity of the liquid resin. Not really practical. Furthermore, Japanese Patent Application Laid-Open No. 58102/1983 proposes an attempt to use 70 to 92% branched unsaturated polyester made of polyhydric alcohol as a liquid photosensitive curable resin composition for printing plates. However, when considering the operability of liquid photosensitive resins, unsaturated polyesters account for the entire resin.
If it accounts for 70 to 92%, the photosensitive resin itself will have poor fluidity, and special measures such as heating will be required during operations such as coating. Furthermore, in order to obtain a branched structure, 10% of polyhydric alcohols with 3 or more hydric alcohols are used.
~70 mol% is used, but this tends to cause gelation during the unsaturated polyester synthesis reaction, and requires a very long reaction at low temperatures or a two-stage reaction or catalysts, etc. It is not practical in manufacturing. The present inventors have arrived at the present invention as a result of intensive studies from the viewpoint of reducing volume shrinkage during curing in commonly used liquid resin compositions having an unsaturated polyester content (40 to 80% by weight). That is, the present invention is a curable resin composition comprising a composition comprising the following (A) and (B) and (C). (A) Unsaturated polyester 40-80 obtained from polycarboxylic acid and glycol having the compositions (1) to (4) below
Weight % (1) Cyclic polycarboxylic acid having at least 3 carboxyl groups or reactive derivative groups thereof, (2) Ethylenically unsaturated group-containing dicarboxylic acid, (3) At least 2 carboxyl groups or their reaction (4) at least one bulky glycol having a branched aliphatic chain and/or alicyclic chain having 50 or less carbon atoms; (B) 20 to 60% by weight of an ethylenically unsaturated group-containing monomer that is compatible with the unsaturated polyester; (C) Polymerization initiator The characteristics of the present invention are as follows. B The cyclic polycarboxylic acid of (A)-(1) above facilitates the control of the acid value during the synthesis of unsaturated polyester,
Moreover, it is highly effective in maintaining the solubility and affinity of the obtained unsaturated polyester resin in dilute aqueous alkaline solutions. (b) The ethylenically unsaturated group-containing carboxylic acid of (A)-(2) plays the role of introducing an unsaturated group into the unsaturated polyester. C) The bulky alicyclic dicarboxylic acid (A)-(3) is a component that exhibits an extremely large effect on reducing volumetric shrinkage during curing, which is the objective of the present invention, and contains a cyclohexane ring, a cyclohexene ring, or a bicyclo ring. It is desirable to use an alicyclic dicarboxylic acid having the following. Bulky glycols having 50 or less carbon atoms in (A)-(4) are components that have a great effect on reducing curing shrinkage, which is the objective of the present invention, and are branched in aliphatic chain glycols. More preferably, the alicyclic chain glycol contains at least one cyclohexane ring, has 16 or more carbon atoms, and has a structure in combination with a branched aliphatic chain. Among the above-mentioned acids and glycols, especially the glycol component, the effect of reducing curing shrinkage, which is the objective of the present invention, is more pronounced when used in combination than when used alone. It is also possible to improve various properties such as hardness and flexibility. (e) The ethylenically unsaturated group-containing monomer (B) is a generally referred to as a "crosslinking monomer" and becomes a three-dimensional structure through a crosslinking reaction with the unsaturated polyester (A) to give a cured product. Good compatibility with the unsaturated polyester is an essential condition; if the compatibility is insufficient, phase separation, cracks, etc. will occur in the cured product after crosslinking, making it unusable. The polymerization initiator (C) also includes thermal polymerization initiators and photopolymerization initiators (so-called sensitizers). The curable resin composition of the present invention can be thermocured or photocured, and by either curing method, a cured product with excellent low shrinkage properties as described above can be obtained. In particular, in the case of photocuring, its advantages can be greatly utilized, such as shortening the curing time, improving workability, and preventing thermal distortion (warping) or coloring (yellowing) during molding. Among the unsaturated polyester components used in the present invention, specific examples of "cyclic polycarboxylic acids having at least three carboxyl groups or reactive derivative groups thereof" include the following: trimesic acid, trimellitic acid, hemimellitic acid, pyromellitic acid, 2,4,5-toluentriecarboxylic acid, 1,3,5-trimethyl-2,4,
6-benzenetricarboxylic acid, benzophenonetetracarboxylic acid, ethylene bistrimellitic acid,
Naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, anthracenetricarboxylic acid, anthracenetetracarboxylic acid, triphenylmethanetricarboxylic acid and acid anhydrides thereof. Specific examples of "ethylenic unsaturated group-containing dicarboxylic acids" include maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, and reactive derivatives thereof. Specific examples of "bulky alicyclic dicarboxylic acids having at least two carboxyl groups or reactive derivative groups thereof" include: hexahydrophthalic acid, tetrahydrophthalic acid, bicyclo [2,2,1]-5-heptene-
2,3-dicarboxylic acid, bicyclo[2,2,2]
-5-octene-2,3-dicarboxylic acid, cyclohexanedicarboxylic acid, lower alkyl group substituted products such as methyl and ethyl, 2-methyl-hexene-1-3,4,5-tricarboxylic acid, and polyhydric carboxylic acids thereof Anhydride of acid. Among "bulky glycols having a branched aliphatic chain or alicyclic chain having 50 or less carbon atoms",
As for "bulky glycol with aliphatic chain",
Branched glycols having lower alkyl substituents are applicable, and specific examples include the following commercially available products: Neopentyl glycol, 2-methyl-2-n
-Propyl-1,3-propanediol, 1,
1,3-trimethyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-methyl-1,5-pentanediol, 1,1,4,4-tetramethylbutane Diol, glycerin monoallyl ether, etc. Also, “bulky glycols with alicyclic chains”
is a glycol having at least one cyclohexane ring or having one cyclohexane ring and a structure combined with a branched aliphatic chain, and specific examples thereof include the following: Can: hydrogenated bisphenol-A, 1,4-cyclohexanedimethanol, hydrogenated bisphenol-A
ethylene oxide adduct (2-10 mol) of hydrogenated bisphenol-A, propylene oxide adduct (2-10 mol) of hydrogenated bisphenol-A. In the present invention, the "ethylenic unsaturated group-containing monomer having compatibility with unsaturated polyester" refers to an ethylenically unsaturated group-containing monomer that acts as a diluent to unsaturated polyester and is capable of addition polymerization to at least this unsaturated polyester. Those having one or more unsaturated groups, including methacrylic acid, methacrylic acid chloride and methacrylic esters, acrylic acid, acrylic acid chloride and acrylic esters, vinyl esters, methacrylamides, acrylamides. , vinyl ethers, styrene and its derivatives, allyl compounds, N-vinyl compounds, etc. Specific examples of methacrylic acid esters include the following: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate. , cyclohexyl methacrylate, benzyl methacrylate,
Octyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, methoxyethyl methacrylate, ethoxyethyl methacrylate, butoxyethyl methacrylate, methoxypolyethylene glycol methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxypentyl methacrylate, hydroxychloropropyl methacrylate, polypropylene Glycol methacrylate, N,N-dimethylamino methacrylate, N,N-diethylamino methacrylate, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, chloroethyl methacrylate, dibromopropyl methacrylate, tribromphenyl methacrylate, allyl methacrylate, oleyl methacrylate, epoxystearyl methacrylate , trimethylolpropane monomethacrylate, diethylene glycol monomethacrylate, pentaerythritol monomethacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexane glycol dimethacrylate, neopentyl glycol dimethacrylate methacrylate, polypropylene glycol dimethacrylate, diglycerine dimethacrylate,
2,2-bis-(4-methacryloxyethoxyphenyl)propane, 2,2-bis-(4-methacryloxydiethoxyphenyl)propane, trimethylolpropane trimethacrylate, etc. Specific examples of acrylic esters include: methyl acrylate, ethyl acrylate, n
-Propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, t-butyl acrylate, cyclohexyl acrylate,
Hydroxylauryl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, carbitol acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate, methoxypolyethylene glycol acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxychloropropyl acrylate, butylene glycol monoacrylate , N,N-dimethylaminoethyl acrylate, N,N-diethylaminoethyl acrylate, glycidyl acrylate,
Tetrahydrofurfuryl acrylate, chloroethyl acrylate, dibromopropyl acrylate, tribromphenyl acrylate, allyl acrylate, epoxystearyl acrylate,
Polyethylene glycol diacrylate, 1,3
-Butylene glycol diacrylate, 1,4-
Butylene glycol diacrylate, 1,6-hexane glycol diacrylate, neopentyl glycol diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, 2,2-bis-(4-acryloxydiethoxyphenyl)propane, 2 ,2-bis-(4-acryloxypropyloxyphenyl)
Propane, trimethylolpropane diacrylate, pentaerythritol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, triacryl formal, tetramethylolmethane tetraacrylate, etc. Examples of vinyl esters include vinyl butyrate, vinyl trimethyl acetate, vinyl caproate, vinyl benzoate, vinyl salicylate, divinyl succinate, divinyl phthalate, and the like. Examples of methacrylamides include methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-arylmethacrylamide, and N-hydroxyethyl-N-methylmethacrylamide; examples of acrylamides include acrylamide, N-methylmethacrylamide, and N-hydroxyethyl-N-methylmethacrylamide. t-butylacrylamide, Nt-octylacrylamide, N
-Methyloacrylamide, N-butoxymethylacrylamide, N-isobutoxymethylacrylamide, diacetone acrylamide and the like. Examples of vinyl ethers include hexyl vinyl ether, octyl vinyl ether, ethylhexyl vinyl ether as alkyl vinyl ether types, vinyl phenyl ether as a vinyl aryl ether type, and polyvinyl ether of polyhydric alcohols. Examples of styrene derivatives include styrene and divinylbenzene having substituents such as alkyl groups, alkoxy groups, halogens, carboxyl groups, and allyl groups at the ortho and/or para positions. Allyl compounds are mainly diallyl esters of dicarboxylic acids, and specific examples include diallyl phthalate, diallyl isophthalate, diallyl terephthalate, diallylhexahydrophthalate, diallylhexahydroisophthalate, diallylhexahydroterephthalate, etc. Examples of the triallyl ester of tricarboxylic acid include triallyl trimellistate. Examples of the N-vinyl compound include N-vinylpyrrolidone, N-vinylimidazole, N-vinyloxazolidone, and N-vinylcarbazole. The amount of the unsaturated group-containing monomer used in the present invention is usually 20 to 60 parts by weight, preferably 30 to 50 parts by weight, based on 100 parts by weight of the unsaturated polyester resin. If the amount used is too large, the properties of the cured product such as solvent resistance, chemical resistance (acid, alkali), flexibility, heat resistance, etc. will be reduced. On the other hand, if the amount is too small, it will be difficult to control the viscosity and the operability of coating etc. will be poor. The "polymerization initiators" that can be included in the resin composition of the present invention include a wide range of initiators used in general thermosetting resin compositions and initiators used in photocurable resin compositions. included. Examples of the thermosetting initiator include organic peroxides such as hydroperoxides, ketone peroxides, dialkyl peroxides, diacyl peroxides, and peroxy esters, and azo compounds. Specific examples of organic peroxides include benzoyl peroxide, di-t-butyl peroxide,
Examples of azo compounds include methyl ethyl ketone peroxide and cumene hydroperoxide, and specific examples of azo compounds include azobisisobutyronitrile. Further, as the photocuring initiator, the above-mentioned organic peroxides and azo compounds can be used, and so-called sensitizers such as carbonyl compounds, organic sulfur compounds, halogen compounds, and photoreducible dyes can also be used. Specific examples of carbonyl compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzophenone, anthraquinone, benzyl dimethyl ketal, etc., and organic sulfur compounds include dibutyl sulfide and benzyl sulfide. The halides include carbon tetrachloride, and the photoreducible dyes include erosin, erythrosin, methylene blue, and the like. The resin composition of the present invention can be cured by heat or light, but in some cases it can also be cured by irradiation with ionizing radiation such as electron beams or radiation. It is not necessary to intentionally include the polymerization initiator in the composition. The amount of the polymerization initiator used is usually 0.05 to 15 parts by weight based on the total amount of the unsaturated polyester resin of the present invention.
The amount is preferably 0.1 to 5 parts by weight. In addition, a polymerization accelerator can be included in the composition along with such a polymerization initiator, if necessary. These include conventionally known amines, aminoketones, aminobenzoic acid esters, phosphines, and thioalcohols such as 2-mercaptobenzimidazole. Examples of polymerization inhibitors that can be added to the resin composition of the present invention include hydroquinone, p-methoxyphenol, t-butylcatechol, pyrogallol, phenothiazine, naphthylamine, diphenylamine, N-nitrosodiphenylamine, and p-toluidine. This usage amount is usually based on the total amount of unsaturated polyester resin of the present invention.
The amount may be 0.005 to 2 parts by weight. In addition to the above-mentioned components, the cured resin composition of the present invention may contain conventionally known additives such as fillers, thixotropic agents, plasticizers, defoamers, and colorants, if necessary. Fillers are usually 0.5 to 150 parts by weight based on the total amount of unsaturated polyester resin, and other additives are usually 0.05 to 10 parts by weight based on the total amount.
It can be used within a range of parts by weight. In curing the cured resin composition of the present invention,
Because this composition has good film-forming properties, it can be applied to various objects, or after being subjected to appropriate casting treatment, it can be heated or irradiated with actinic rays.
In some cases, ionizing radiation may be irradiated.
The most desirable method is photocuring using actinic light such as ultraviolet rays, which has many advantages such as shortening the curing time and significantly preventing warping and yellowing of the cured product. As mentioned above, the cured resin composition of the present invention reduces volumetric shrinkage during curing and provides good properties of the cured product, so that it can be used as a protective coating material for electrically insulating materials, as a paint, etc.
Not only can it be used in a wide range of applications such as adhesives, photoresist materials, photosensitive resin plates, displays, and laminated materials, but it can also be used in various other types of hardening molding, such as fiber processing, reinforcing and protecting plastics and glass, and protecting metal surfaces. You can. EXAMPLES The present invention will be explained in detail and concretely using examples below. In addition, "parts" in the examples are "parts by weight"
"Acid value" is "the number of milligrams of potassium hydroxide required to neutralize 1 gram of a sample." Moreover, the volume shrinkage rate (%) was calculated by the following formula. Volume shrinkage rate = AB/A x 100 (%) However, A is the density of the cured product B is the density of the resin liquid Example 1 319 parts of fumaric acid, 192 parts of trimellitic anhydride,
210 parts of 4-methyltetrahydrophthalic anhydride, 159 parts of diethylene glycol, 208 parts of neopentyl glycol, and 491 parts of a propylene oxide adduct (4 mol) of hydrogenated bisphenol-A were mixed at 100 to 130°C for 0.5 hours under _{an N2} atmosphere. Then at 180-210℃
The reaction was carried out for 3.5 hours to synthesize an unsaturated polyester with an acid value of 127. 65 parts of this unsaturated polyester, 6 parts of methacrylamide, 29 parts of diallylisophthalate, 1.0 part of benzoin ethyl ether, 0.045 part of 2-mercabutobenzimidazole and 0.018 part of N-nitrosodiphenylamine were mixed to form a photocurable resin. A product was obtained (referred to as resin A). Resin B was obtained in exactly the same manner as in Resin A except that 29 parts of diallyl hexahydrophthalate was used instead of diallyl isophthalate. Similarly, Resin C and Resin "Comparative 1" were obtained by conventional methods as shown in Table 1. These obtained resins were photocured as follows. In other words, a negative film is placed on a horizontally placed glass plate, and a 9 micron thick polyethylene terephthalate film is closely stacked on top of it.
Furthermore, the resin composition shown in Table 1 was applied thereon to a thickness of 0.7 mm. Next, a 0.125 mm polyethylene terephthalate film was placed on top of this resin, and exposed from the negative film side for 5 minutes using a light source consisting of eight 60 W ultraviolet fluorescent lamps. The unexposed area was removed by washing with a dilute alkaline aqueous solution and then dried. The obtained cured product was sufficiently hard and tough. The densities of the cured resins and resin liquids shown in Table 1 were measured, and the volumetric shrinkage rates were calculated and shown in Table 1. Compared to Comparative 1, resins A, B, and C of the present invention examples have
The volumetric shrinkage rate is significantly reduced.

【table】

[Table] [However, in this specification, FA: fumaric acid,
TMA: trimellitic anhydride, Me-HHPA: 4
-Methylhexahydrophthalic anhydride, PAn: phthalic anhydride, DEG: diethylene glycol,
NPG: neopentyl glycol, PD: 1,5-
Pentanediol, HPO-20: 2 mole propylene oxide adduct of hydrogenated bisphenol-A,
HPO-40: 4 mole propylene oxide adduct of hydrogenated bisphenol-A, DAiP: diallyl isophthalate, DAHP: diallyl hexahydrophthalate, Each resin in Table 1 contains 1.0 parts by weight of benzoin ethyl ether, 2- Contains 0.045 parts by weight of mercaptobenzimidazole and 0.018 parts by weight of N-nitrosodiphenylamine. Example 2 As shown in Table 2, the molar ratio of fumaric acid, trimellitic anhydride, hexahydrophthalic anhydride, diethylene glycol, and ethylene oxide adduct of hydrogenated bisphenol-A (2 moles) was 60:20:20. The molar ratio of unsaturated polyester (acid value 140), fumaric acid, trimellitic anhydride and diethylene glycol is 60:30: 80:
An unsaturated polyester having a ratio of 20:90 (acid value 150) was synthesized in the same manner as in Example 1 according to the single method. 2
Resins D, E, Comparative 2, and Comparative 3 having the compositions shown in Table 2 were prepared from various unsaturated polyesters. The obtained four types of resins were irradiated with ultraviolet rays in the same manner as in Example 1 to obtain cured products. All had sufficient hardness and strength. The volume shrinkage rate was calculated from the density of the cured product and the resin liquid, and is shown in Table 2.

【table】

[Table] [However, in this specification, HHPA: hexahydrophthalic anhydride, HEO-20: 2 mole ethylene oxide adduct of hydrogenated bisphenol-A, DAP:
Diallyl phthalate, NK ester 4G: Tetraethylene glycol dimethacrylate, benzoin ethyl ether 1.2 for any resin in Table 2.
Part by weight, 2-mercaptobenzimidazole 0.05
parts by weight, including 0.015 parts by weight of N-nitrosodiphenylamine. ] Also, the warp h (mm) was measured as shown in Figure 1,
The edge and width l (μ) of the relief were measured as shown in FIG. However, in the figure, 1 indicates a cured resin, and 2 indicates a steel plate. The warpage h (mm) of test pieces was prepared and measured as follows. That is, a 10 cm square fully cured plate was prepared by performing the same process as in Example 1 except that a 0.3 mm steel plate having an antihalation layer and an adhesive layer was used instead of the 0.125 mm film overlaid on the resin. I made it. When the cured product side is facing up, there is a concave warp, so measure the depth h (mm).
In this case, it was defined as (warp). The results are shown in Table 2. The less warpage, the better. Further, the edge and width l (μ) of the relief was determined as follows. That is, in the exposure process of Example 1, 5 mm
Exposure treatment was carried out using a negative film with a drawing board of φ and a 0.3 mm steel plate in the same way as the warped test piece above. The obtained cured product is a three-dimensional image (relief) with a diameter of 5 mm and a height of 0.7 mm, and its upper surface is the periphery (edge).
Compared to
And so. The results are shown in Table 2. The smaller the edge and width, the better, and when the cured product is used as a printing plate, clear printed matter with less fading etc. can be obtained. From the results in Table 2, resins D and E of the invention examples
Compared to the resins of Comparison 2 and Comparison 3, the results were excellent in terms of volumetric shrinkage, warpage, and edge and width. Example 3 Four types of unsaturated polyesters having the molar ratio shown in Table 3 were synthesized according to a conventional method, and 76 parts of each unsaturated polyester, 4 parts of methacrylamide, 20 parts of diallyl phthalate, and 0.7 parts of benzoin methyl ether were synthesized.
Resins F, G, H and Comparative 4 were obtained, each containing 0.04 part of 2-mercaptobenzimidazole and 0.01 part of p-methoxyphenol. When exposing these resins, each cured product was obtained in the same manner as in Example 1, except that a 2KW high-pressure mercury lamp was used instead of a 60W ultraviolet fluorescent lamp.
All of these cured products had sufficient hardness and toughness. The volume shrinkage rate was calculated from the density of the obtained cured product and resin liquid and is shown in Table 3. Resin F of the present invention example,
Both G and H have lower volumetric shrinkage rates than the comparative example resin (comparison 4).

[Table] However, in this specification, Me-NA: methyl hymic anhydride (Hitachi Chemical), MPPD: 2-methyl-2
-n-propyl-1,3-propanediol,
TMPD: 1,1,3-trimethyl-1,3-propanediol, HEO-40: 4 mole ethylene oxide adduct of hydrogenated bisphenol-A,
EG: Ethylene glycol, 0.7 parts of benzoin methyl ether, 2-
Contains 0.04 part of mercaptobenzimidazole and 0.01 part of p-methoxyphenol. Example 4 Acid and glycol having the composition (charged molar ratio) shown in Table 4 were used as reaction components, and the reaction was carried out at 100 to 130°C for about 1 hour and at 150 to 220°C for about 7 hours in an N ₂ atmosphere.
Unsaturated polyesters with the acid values shown in the table passed the test. This unsaturated polyester was then dissolved in styrene monomer to give a resin content of 70 and 45% by weight, respectively.
0.025 parts by weight of hydroquinone as an inhibitor was added and mixed to obtain six types of unsaturated polyester resins shown in Table 4. These resins are heated at 60 to 75℃ in a glass partition plate.
By heating for 3 hours at 150℃ and 2 hours at 150℃,
A cured test piece with sufficient hardness was obtained. The volume shrinkage rate was calculated from the density of this cured product and each resin liquid and is shown in Table 4. Resins J to M of the invention examples are Comparative 4
And compared to Comparison 5, the volumetric shrinkage rate was extremely low.

[Table] However, in this specification, PG: propylene glycol,
HEO-80: ethylene oxide adduct of hydrogenated bisphenol-A (8 moles), all resins in Table 4 contain 0.025 parts of hydroquinone and 0.5 parts of benzoyl peroxide.

[Brief explanation of drawings]

The drawings illustrate a method of measuring the effectiveness of the invention. FIG. 1 is a diagram showing a method for measuring warpage h (mm), and FIG. 2 is a diagram showing a method for measuring relief edge/width l (μ). In the figure, 1 indicates a cured resin, and 2 indicates a steel plate. In addition, h indicates the depth of warpage, and l indicates the degree of curvature.

Claims (1)

[Scope of Claims] 1. A curable resin composition comprising a composition comprising the following (A) and (B) and (C). (A) Obtained from a carboxylic acid component consisting of the following (2) and (3) or (1), (2) and (3) and a glycol component containing at least 20 mol% of (4) in the glycol component. 40-80% by weight of unsaturated polyester. (1) Cyclic polycarboxylic acid having at least three carboxyl groups or reactive derivative groups thereof; (2) dicarboxylic acid containing ethylenically unsaturated groups; (3) at least two carboxyl groups or reactive derivatives thereof. at least one bulky alicyclic dicarboxylic acid having a group, (4) an ethylene oxide adduct of hydrogenated bisphenol A (2 to 10 moles) or a propylene oxide adduct of hydrogenated bisphenol A (2 to 10 moles);
(B) 20 to 60% by weight of an ethylenically unsaturated group-containing monomer that is compatible with the unsaturated polyester; (C) Polymerization initiator 2 (3) of (A) above; 2. The curable resin composition according to item 1, wherein the curable resin composition has a cyclohexane ring, a cyclohexene ring, or a bicyclo ring. 3. The curable resin composition according to item 1 or 2, wherein (4) in (A) has at least one cyclohexane ring and has 16 or more carbon atoms. 4. The curable resin composition according to any one of items 1 to 3, wherein (1) in (A) is trimellitic acid or trimellitic anhydride. 5 Items 1 to 4, where (2) of (A) above is fumaric acid.
Any of the curable resin compositions described in . 6. The curable resin composition according to items 1 to 5 above, which further contains at least one glycol having a branched aliphatic chain in addition to (4) of (A). 7. The curable resin composition according to any one of items 1 to 5, wherein (B) contains at least one aromatic ring or cyclohexane ring. 8. The curable resin composition according to any one of items 1 to 6, which is photocurable.