JPS6210522B2 - - Google Patents

Description

[Detailed description of the invention]

In this invention, a bisphenol-based liquid epoxy resin contains, as a base polymer, a modified epoxy resin having a special functional group added by a half-ester compound of an aromatic polycarboxylic acid and an acidic phosphoric acid ester. This relates to a photocurable composition. The photocurable composition of the present invention has a fast photocuring speed, and various physical properties of the photocured product after photocuring (e.g., pencil hardness, bending resistance, adhesion/adhesiveness, etc.) are at a high level. It has excellent heat resistance (soldering heat resistance) and electrical insulation, and can be used for coatings and electrical component materials. Japanese Patent Publication No. 49-14128 discloses that a compound obtained by esterifying a hydroxy group-containing vinyl monomer and a saturated cyclic carboxylic acid anhydride (half-ester compound) is reacted with an epoxy resin. A photocurable composition whose base polymer is a modified epoxy resin having vinyl groups at both ends is described. However, the known photocurable compositions containing the above-mentioned modified epoxy resins do not have sufficiently satisfactory adhesion to the surfaces of metals (aluminum, tinplate, copper), synthetic resins, etc. in their photocured films. Nakatsuta. The inventors developed a photocurable film based on a modified epoxy resin that has sufficiently high adhesion (adhesiveness) to any surface such as synthetic resin, aluminum, tinplate, copper, etc. As a result of intensive research into curable compositions, we have arrived at a photocurable composition mainly composed of the special modified epoxy resin of this invention. That is, in this invention, about 25 to 65% of the total epoxy groups in the bisphenol-based liquid epoxy resin are
It is added by a half-ester compound obtained by the esterification reaction of aromatic polyhydric carboxylic acids and hydroxy group-containing (meth)acrylate, and 80% of the remaining epoxy groups in the epoxy resin are added.
The above relates to a photocurable composition containing, as a base polymer, a modified epoxy resin added with an acidic phosphoric acid ester having a (meth)acryloyl group. Here, the fact that the epoxy group of the epoxy resin is added with a half-ester compound or an acidic phosphate ester means that the epoxy ring of the epoxy resin is generally opened by the acidic group of each compound, This means that the epoxy resin and the compound are bonded together by forming an ester bond with each compound at the same time as ring opening. Therefore, the modified epoxy resin of this invention is
It is a modified product of a special epoxy resin that has both a functional group created by the addition of a half-ester compound and a functional group created by the addition of an acidic phosphoric acid ester. The photocurable composition of the present invention becomes a photocurable film with extremely excellent adhesion (adhesiveness) due to the action of the special functional group of the modified epoxy resin, and the photocuring speed (belt The photocured film exhibits high physical properties (pencil hardness, bending resistance, etc.). Further, by photocuring, this photocurable composition becomes a photocured product with high solder heat resistance and excellent electrical insulation properties. Generally, as shown in JP-A No. 48-12889, a photocurable composition using an acidic phosphate ester together with a compound having an epoxy group (epoxy resin) has an electrically conductive property rather than an electrically insulating property. Although it was known that the photocurable composition of the present invention is a photocurable product that has properties as a main component, it is Regardless, it is unexpected that the photocured product has excellent electrical insulation properties (volume resistivity), and is a feature of the present invention. In this invention, in the modified epoxy resin, about 25 to 65%, preferably 30 to 60%, of the total epoxy groups in the bisphenol-based liquid epoxy resin are aromatic polyhydric carboxylic acids and hydroxy group-containing (meth)acrylates. 80% or more, preferably 90% or more of the remaining epoxy groups of the epoxy resin have a (meth)acryloyl group. It is added by an ester. The bisphenol-based liquid epoxy resin, which is a raw material for the above-mentioned modified epoxy resin, is a bisphenol compound [for example, 2,2-bis(4'-hydroxyphenyl)propane, bis(4'-hydroxyphenyl)methane] , or their halides) and epichlorohydrin, and has a rotational viscosity (at 25°C) of 90 to 50,000 centipoise, especially
It may be about 100 to 20,000 centipoise and its epoxy equivalent is about 140 to 250, particularly about 150 to 220. The half-ester compound added to the liquid epoxy resin is produced by esterifying the acid anhydride group or carboxyl group of aromatic polyvalent carboxylic acids with a hydroxy group-containing (meth)acrylate, A compound having at least one carboxyl group and at least one (meth)acryloyl group in one molecule of the half-ester compound, in particular, the molecular weight of the half-ester compound is 1000 or less, more preferably 500 The following are preferred. The half-ester compounds are, for example, ortho-, meta- or para-phthalic acid, trimellitic acid, pyromellitic acid, 2,3,3',4'-biphenyltetracarboxylic acid, 3,3',4,4'- Aromatic polycarboxylic acids such as biphenyltetracarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, or their acid anhydrides, and 2-hydroxyethyl (meth)acrylate, 2- Hydroxy group-containing acrylate or methacrylate such as hydroxypropyl (meth)acrylate, diethylene glycol mono(meth)acrylate, dipropylene glycol mono(meth)acrylate, and triethylene glycol mono(meth)acrylate under known half-esterification reaction conditions. Any product obtained by reaction may be used. Approximately 25 to 65 of the total epoxy groups in the aforementioned epoxy resin
% with the half-ester compound, the liquid epoxy resin and the half-ester compound are mixed with triethylbenzylammonium chloride, methyltriethylammonium chloride, tetraethylammonium chloride, methyltriethylammonium iodine. The reaction can be carried out for 5 to 10 hours at 60 to 100°C, especially 70 to 90°C, in the presence of an esterification catalyst such as an organic quaternary ammonium salt such as dide, without a solvent or in an organic solvent. . In the reaction method, the ratio of the liquid epoxy resin and the half-ester compound used is preferably such that the half-ester compound is used in an amount of about 80 to 300 parts by weight per 100 parts by weight of the liquid epoxy resin. Added to the above liquid epoxy resin (meth)
An acidic phosphoric acid ester having an acryloyl group is defined as having at least one (meth)acryloyl group at the end, especially 1 to 3, and at least one hydroxyl group (acidic group) directly bonded to a phosphorus atom.
In particular, it is an acidic phosphoric acid ester having 1 to 2 esters,
For example, the general formula [However, in the above general formula, R is hydrogen or a methyl group, A is a residue other than the hydroxyl group used in the ester bond in the previous formula of a diol compound or other polyhydric alcohol compound, and further the subscript x is 1-3, and n is 1-2. Acidic phosphoric acid esters shown by ] can be preferably mentioned. The acidic phosphoric acid ester may be produced by any known method as long as the above-mentioned phosphoric ester can be produced. As a method for producing the acidic phosphoric acid ester represented by the above general formula, for example, by reacting a (meth)acrylate compound having a hydroxy group with phosphoryl chloride (POCl ₃ ), phosphoric acid, phosphorus pentoxide, etc. The manufacturing method can be mentioned. As the (meth)acrylate having a hydroxy group used in the above production method, the same hydroxy group-containing (meth)acrylate as used in producing the above-mentioned half-ester compound can be mentioned. In order to add an acidic phosphoric ester to the epoxy group of a liquid epoxy resin, for example, the liquid epoxy resin and the acidic phosphoric ester are heated at about 5 to 80°C, especially at 10 to 80°C, without a solvent or in an organic solvent. The reaction may be carried out with stirring at a reaction temperature of 50° C. for about 0.1 hour or more, particularly about 0.5 to 5 hours. In the production of modified epoxy resin, the order in which a half-ester compound and an acidic phosphoric acid ester are added to a liquid epoxy resin may be such that either compound may be added first, or both may be subjected to an addition reaction at the same time. However, in particular, acidic phosphoric acid esters are unstable at high temperatures and have much higher reactivity with epoxy resins than half-ester compounds, so first, add the half-ester compound to the epoxy resin,
A method for producing a modified epoxy resin in which the intermediate reaction product is then subjected to an addition reaction with an acidic phosphoric acid ester is suitable. According to the above-mentioned method, the epoxy groups of the liquid epoxy resin are almost completely added by the half-ester compound and the acidic phosphoric acid ester, so that the resulting modified epoxy resin has almost no remaining epoxy groups. As a result, a modified epoxy resin with excellent storage stability can be obtained. In addition, in this invention, this modified epoxy resin has each functional group bonded by addition of the aforementioned half-ester compound and acidic phosphoric acid ester, and also has other acidic compounds (for example, phosphoric acid, Phosphorus compounds such as acidic phosphoric acid alkyl esters, phosphorous acid, and acidic phosphite esters, or inorganic acids such as hydrochloric acid and nitric acid, acetic acid, propionic acid, maleic acid, fumaric acid, phthalic acid, pyromellitic acid, and biphenyltetracarboxylic acid. organic acids such as acids) may have a functional group or substituent partially added to and bonded to the epoxy group of the (modified) epoxy resin. In this invention, the photocurable composition has the above-mentioned modified epoxy resin as a base polymer, and in addition to the modified epoxy resin, a photopolymerizable monomer blended in a known photocurable composition is used. A photosensitizer, a photosensitizer, and other additives may be included. In this invention, 100 parts by weight of the above-mentioned modified epoxy resin, 30 to 800 parts by weight of the photopolymerizable monomer, especially 50 to 800 parts by weight,
700 parts by weight, and photosensitizer, 0.5 to 15 parts by weight,
In particular, a photocurable composition containing 0.5 to 10 parts by weight is preferred. The photopolymerizable monomer may be any compound as long as it has a photopolymerizable unsaturated bond, and in this invention, in particular,
(Meth)acrylate compounds obtained from acrylic acid or methacrylic acid are preferred. The (meth)acrylate photopolymerizable monomer is
For example, glycol compounds (including their condensates), organic diols (butanediol, heptanediol, hexanediol, etc.), polyhydric alcohols, or oligoesters of these and organic polycarboxylic acids are used to (meth)acrylic acid Various (meth)acrylate compounds obtained by esterification reaction with organic acids such as acetic acid, propionic acid, maleic acid, fumaric acid, phthalic acid, pyromellitic acid, biphenyltetracarboxylic acid, or phosphoric acid, Preferred examples include various (meth)acrylate compounds obtained by esterifying inorganic acids such as phosphorous acid and nitric acid with hydroxy group-containing (meth)acrylates. Therefore, in this invention, the half-ester compound and acidic phosphate ester used in the production of the modified epoxy resin, and the hydroxy group-containing (meth)acrylate used in the production of the half-ester compound and the acidic phosphate ester, are too,
It has a (meth)acryloyl group and can be suitably used as the photopolymerizable monomer. In addition to the above-mentioned compounds, examples of the photopolymerizable monomer include 2-ethylhexyl (meth)
Acrylate, lauryl (meth)acrylate,
Ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate,
propylene glycol di(meth)acrylate,
Polypropylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate
Preferred examples include acrylate, trimethylolpropane tri(meth)acrylate, and the like. Examples of the photosensitizer include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin butyl ether, benzoin, α-methylbenzoin, α
- chlordioxybenzoin, benzophenone,
Examples include dimethoxyphenylacetophenone and benzyl. The photocurable composition of the present invention contains hydroquinone, 2,6-di-tertiary butylpara-cresol, parabenzoquinone, etc. as a thermally polymerizable stabilizer.
5% by weight or less, especially 3% by weight based on the total photocurable composition
It is preferable to use it in an amount of % by weight or less. The method for preparing the photocurable composition of the present invention (the method for blending each component) is not particularly limited. In this invention, when producing the above-mentioned modified epoxy resin, if a photopolymerizable monomer that is inactive in the esterification reaction is used as a reaction solvent, the modified epoxy resin and the photopolymerizable monomer can be combined with each other after the addition reaction. A mixture of the photosensitive monomer and the photopolymerizable monomer is obtained as a reaction solution. Preferably, a photocurable composition is prepared. The photocurable composition of the present invention is a colorless transparent liquid, and preferably has a rotational viscosity (at 25° C.) of about 100 to 50,000 centipoise, particularly about 150 to 10,000 centipoise. The photocurable composition of this invention has, as a modifier,
Small amounts of higher fatty acid amides and waxes may be added, monomers, organic solvents, etc. may be added as viscosity modifiers, and inorganic pigments and organic pigments may also be added. Examples, comparative examples, and reference examples are shown below. In the Examples and Comparative Examples, the photocuring speed of the photocurable composition was determined by applying the photocurable composition to a thickness of approximately 10μ on a degreased aluminum plate using a 2KW high-pressure mercury lamp (Iwasaki) with a length of 25cm. (manufactured by Denki Co., Ltd.) is placed on the belt of an ultraviolet irradiator equipped with a belt that moves horizontally 9 cm vertically downward, and the photocurable composition coating is photocured by running the belt at a predetermined speed. After pressing your finger against the surface of the coating film, observe the surface of the coating film for fingerprints or cloudiness, and indicate the belt's maximum feed speed (m/min) when no fingerprints or cloudiness occur on the coating surface. Ta. The adhesion (adhesiveness) of a photo-cured coating film is measured by applying a photo-cured coating film vertically and horizontally on an aluminum, tin plate, copper plate, or alkyd resin plate obtained by photo-curing under the same conditions as those used to measure the photo-curing speed. Make 100 goblets by making 2mm wide straight cuts, apply Sellotape (registered trademark), then peel off the tape and calculate the number of goblets remaining on the aluminum, tin, copper plate, or alkyd resin plate. Indicated. The boiling resistance (adhesion after boiling) of the photocured coating film is
Each photocurable composition is applied to a thickness of about 30μ on an aluminum, tinplate or alkyd resin plate,
The photocured coating film obtained by photocuring three times at a belt feed speed of 1 m/min was immersed in hot water at 100°C for 1 hour, and then the adhesion test was performed in the same manner as the adhesion test described above to determine the number of remaining goblets. Ta. The pencil hardness of the photo-cured coating film was determined using a photo-cured film that was photo-cured under the same conditions as those used to measure the photo-curing speed.
Measured according to JIS-K5400-6.14. The bending resistance of a photocurable coating film is obtained by applying a photocurable composition to a thickness of approximately 30 μm on an iron plate specified in JIS-K5400 and photocuring it three times at a belt feed rate of 1 mg/min. JIS-K5400 using the sample
- Measured in accordance with 6.13. Solder heat resistance was determined by immersing a copper plate coated with a photocured film in molten solder at 270°C for 30 seconds and observing the state of the coating film. The volume resistivity was measured using a microcurrent potentiometer manufactured by Takeda Riken Co., Ltd. on a sample (photocured product) with a thickness of 1 mm and a diameter of 100 mm. Reference Examples 1 to 5 (Production of half-ester compound) 2-hydroxyethyl acrylate (hereinafter referred to as 2
-HEA) and 98.8 parts by weight of phthalic anhydride were reacted at 95°C for 8 hours in the presence of 0.3 parts by weight of 2,6-tert-butyl-para-cresol to form a carboxyl group containing one carboxy group. and 1 acryloyl group
Contains 82.0% by weight of a half-ester compound with 2
-A reaction solution containing 18.0% by weight of HEA (unreacted) was obtained. The completion of the esterification reaction was confirmed by the disappearance of the absorption peaks (1850 cm ^-1 and 1770 cm ^-1 ) in the infrared absorption spectrum of the acid anhydride ring of phthalic anhydride. (Manufacture of modified epoxy resin) Bisphenol A type epoxy resin (manufactured by Ciel, Epicoat 828, epoxy equivalent 190, molecular weight approx.
380) 190 parts by weight, 322 parts by weight of a reaction solution containing the half-ester compound produced as described above (half-ester content: 82% by weight, 2-HEA content: 18% by weight), and 2- A mixed solution was prepared by adding 128 parts by weight of hydroxypropyl acrylate (hereinafter referred to as 2-HPA), and to the mixed solution,
1.9 parts by weight of triethylbenzylammonium chloride as a catalyst and 2.6 parts by weight as a thermal polymerization stabilizer
- Add 0.6 parts by weight of tertiary butyl-para-cresol and carry out an addition reaction with the entire mixture at 85°C for the time shown in Table 1 to form an epoxy resin in the proportions shown in Table 1. A reaction solution () containing an intermediate product in which an epoxy group was added with a half-ester compound was obtained. Next, acidic phosphoric acid ethylene acrylate ester (manufactured by Nippon Kayaku Co., Ltd., acid value: 322.5) in the amount shown in Table 1 was added to the reaction solution (2000) to give a
The mixture was stirred at 30 to 50°C for about 1 hour to obtain a reaction solution (2) containing a modified epoxy resin in which the remaining epoxy groups of the intermediate product were added with acidic phosphoric acid ester. Table 1 shows the composition of the aforementioned reaction solution (), the content of modified epoxy resin in the reaction solution (), and the rotational viscosity (25° C.) of the reaction solution (). In addition, in addition to the modified epoxy resin, the reaction solution () contains substantially the same amount of half-ester compounds, 2-HEA, and 2-HPE that are present in the reaction solution (), and contains unreacted epoxy resin. Substantially no acidic phosphoric acid ester was contained. Reference Example 6 (Production of half-ester compound) A reaction solution containing 82% by weight of a half-ester compound and 12% by weight of 2-HEA was obtained in the same manner as in Reference Example 1 above. (Production of modified epoxy resin) 174.4 parts by weight of the same bisphenol A type epoxy resin as in Reference Example 1, 298 parts by weight of a reaction solution containing the half-ester compound produced as described above, and oligoester diacrylate ( A mixed solution was prepared by adding 200 parts by weight of Aronix 6100 (manufactured by Toagosei Co., Ltd.), and triethylbenzylammonium chloride was added as a catalyst to the mixed solution.
1.8 parts by weight and 1.5 parts by weight of 2,6-tert-butyl-para-cresol as a thermal polymerization stabilizer were added, and the entire mixture was subjected to an addition reaction at 90°C for about 20 hours. A reaction solution (2) was obtained containing an intermediate product in which the epoxy groups of the epoxy resin were added with a half-ester compound in the proportions shown in . Next, acidic phosphoric acid ethylene acrylate ester (manufactured by Nippon Kayaku Co., Ltd., Kayama-PM ₂ , acid value: 285) and oligoester diacrylate (manufactured by Toagosei Co., Ltd.) were added to the reaction solution () in the amounts shown in Table 1. , Aronix 6100) and stirred at about 30 to 50°C for about 2 hours to form a reaction containing a modified epoxy resin in which the remaining epoxy groups of the intermediate product have been added with acidic phosphoric acid ester. A liquid () was obtained. Table 1 shows the composition of the aforementioned reaction solution (), the content of modified epoxy resin in the reaction solution (), and the rotational viscosity (25° C.) of the reaction solution (). Note that the reaction solution (2) contained substantially no unreacted acidic phosphoric acid ester.

[Table] Examples 1 to 3 and Comparative Examples 1 to 2 An appropriate amount of the reaction solution () produced in Reference Examples 1 to 5 was used, and 2-
100 parts by weight of HPA, 50 parts by weight of pentaerythritol triacrylate (hereinafter referred to as PETA), and benzoin ethyl ether (5% by weight based on the total photocurable composition) as a photosensitizer were added, and Table 2 The composition and rotational viscosity (25
A photocurable composition (for coating) was prepared. The photocuring speed (belt feeding speed) of those photocurable compositions, and the various materials of the photocurable film (archite resin, aluminum, and tinplate)
Table 2 shows the adhesion to the surface of the plate and the boiling resistance. Comparative Example 3 Using an appropriate amount of the reaction solution () containing the intermediate product produced in Reference Example 3, the reaction solution ()
100 parts by weight of 2-HPA, 50 parts by weight of PETA, and benzoin ethyl ether (5% by weight based on the total photocurable composition) as a photosensitizer were added to give the composition and rotational viscosity shown in Table 2. (twenty five
℃) was prepared. Table 2 shows the photocuring speed of the photocurable composition and the adhesion and boiling resistance of the photocured film. In addition, as the composition of the photocurable composition in Table 2,
Photosensitizers and the like were not described.

[Table] Examples 4 to 5 and Comparative Examples 4 to 5 Using the reaction solutions produced in Reference Examples 1, 3, 5, and 6, benzoin ethyl ether was added to each reaction solution as a photosensitizer. (% by weight based on the total photocurable composition) were added to prepare photocurable compositions (for electrical components) having the composition and rotational viscosity (25° C.) shown in Table 3. The photocuring speed (belt feeding speed) of these photocurable compositions and the photocuring test results (pencil strength, flexibility, copper plate adhesion, soldering heat resistance, and volume resistivity) of these photocurable compositions are It is shown in Table 3. Comparative Example 6 A photosensitizer was added in the same manner as in Example 4, except that an appropriate amount of the reaction solution () containing the intermediate product produced in Reference Example 3 was used, and a photocurable composition was prepared. did. The results are shown in Table 3.

【table】

Claims (1)

[Claims] 1 Approximately 25 to 65% of the total epoxy groups in a bisphenol-based liquid epoxy resin are added by a half-ester compound obtained by an esterification reaction between an aromatic polyhydric carboxylic acid and a hydroxy group-containing (meth)acrylate. A photocurable composition containing, as a base polymer, a modified epoxy resin in which 80% or more of the remaining epoxy groups of the epoxy resin are added by an acidic phosphoric acid ester having a (meth)acryloyl group. thing.