JPH0569122B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to an unsaturated polyester resin composition for cathode ray tube processing. (Prior art) As shown in FIG. 1, a method for bonding a cathode ray tube and a front glass is to attach a front glass 3 of approximately the same size and having the same curvature to the face plate portion 2 of a cathode ray tube 1 at minute intervals. Generally, they are separated and surrounded and held by a tape 4, and a resin composition 5 such as an epoxy resin composition or an unsaturated polyester resin composition is filled into this gap and cured. Conventional epoxy resin compositions and unsaturated polyester resin compositions for bonding cathode ray tubes and front glass have their advantages and disadvantages, and a resin composition for bonding cathode ray tubes and front glass satisfies both properties and workability. The current situation is that this has not been obtained. For example, epoxy resin compositions have strong adhesive strength and are convenient for adhering the front glass to the face plate, but due to their nature, they have a considerable coloring property, so they are not suitable for coloring products such as color cathode ray tubes. It is not desirable for things that are considered important. Furthermore, in the case of color cathode ray tubes, which have high added value, recovery is also important, and in the case of epoxy resin, the adhesive strength is strong, so the face plate can be easily damaged when the front glass is removed. , it is nearly impossible to peel this glass off. Furthermore, since epoxy resin compositions have a higher viscosity than unsaturated polyester resin compositions, they have the disadvantage that bubbles that are mixed in during mixing of a curing agent or injection of resin are difficult to remove. Moreover, the viscosity of epoxy resin increases rapidly immediately after mixing with the hardening agent, so the pot life for injection is very short, and special mixing equipment and injection equipment are required to perform the work smoothly, resulting in poor workability. Very inferior. On the other hand, unsaturated polyester resin compositions generally have a relatively low viscosity of a few poise, making it easy to mix the curing agent and inject the resin between the cathode ray tube face plate and the front glass. Although it has advantages such as good bubble removal during mixing and injection, if the ratio of the curing agent used by several percent to the unsaturated polyester resin composition changes from the specified conditions, curing distortion may occur locally during curing. This hardening distortion becomes a lens effect and appears as stripes or bright spots on the screen when the cathode ray tube is operated. These striped patterns and bright spots impair the value of the product, so careful attention must be paid to the mixing ratio of the curing agent. Moreover, since curing distortion occurs due to rapid heating or uneven temperature in the curing furnace, sufficient temperature control must be carried out. Although unsaturated polyester resin compositions have many manufacturing problems as mentioned above, they have low viscosity and easy foam removal, are less colored and have excellent transparency, and cathode ray tubes can be recovered relatively easily. There is an advantage that it can be done. However, because of its poor adhesive strength, it also has the disadvantage of peeling off from the face plate or front glass when the cathode ray tube is operated for a long time. (Objective of the invention) The present invention was made in order to take advantage of the advantages of unsaturated polyester resin while eliminating the surface defects that are the drawbacks of the conventional technology. An object of the present invention is to provide an unsaturated polyester resin composition for cathode ray tube processing that prevents the occurrence of surface defects due to curing distortion and the like. (Means for Solving the Problems) The present invention is produced by reacting an acid component containing an unsaturated dibasic acid and/or its acid anhydride, and optionally other polybasic acid with an alcohol component. An unsaturated polyester having a molecular weight of 500 to 8000 per mole of unsaturated groups to be added to styrene and/or its derivatives and monoesters and/or diesters of unsaturated dibasic acids, (a) and the number of moles of unsaturated groups in styrene and/or its derivatives.
(b), when the number of moles of unsaturated groups in the monoester and/or diester of unsaturated dibasic acid is (c), (b)/{(a)+(c)}=1/10~ The present invention relates to an unsaturated polyester resin composition for cathode ray tube processing, which contains 100 parts by weight of an unsaturated polyester resin composition dissolved in a ratio of 10/1 and 0.5 to 10 parts by weight of maleic anhydride. In the present invention, unsaturated dibasic acids and/or their acid anhydrides used as the acid component include maleic acid, fumaric acid, itaconic acid, citraconic acid, and maleic anhydride. Two or more of these may be used in combination. Other polybasic acids that may be used as necessary in the present invention include phthalic acid, phthalic anhydride,
Isophthalic acid, terephthalic acid, trimellitic acid,
trimellitic anhydride, succinic acid, azelaic acid,
Adipic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic acid, hexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, anthracene-maleic anhydride adduct, rosin-maleic anhydride adduct, Hett's acid, Hett's anhydride Acids, chlorinated polybasic acids such as tetrachlorophthalic acid and tetrachlorophthalic anhydride, and halogenated polybasic acids such as tetrapromophthalic acid and tetrabromophthalic anhydride. Two or more of these may be used in combination. Alcohol components include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6
-hexanediol, triethylene glycol,
Dihydric alcohols such as neopentyl glycol, trihydric alcohols such as glycerin and trimethylolpropane, and tetrahydric alcohols such as pentaerythritol can be used. It is also possible to use halogenated alcohols such as chlorinated and brominated alcohols. The production method for producing unsaturated polyester by reacting the above acid component and alcohol component is mainly carried out by proceeding with a condensation reaction, and low molecules such as water produced when both components react are removed from the system. Proceed by letting go. The reactor used for this reaction is made of glass, stainless steel, or other material that is inert to acid components, and includes a stirring device, a fractionating device to prevent distillation of the alcohol component by azeotropic distillation of water and the alcohol component, It is preferable to use a reaction apparatus equipped with a heating device for increasing the temperature of the reaction system, a temperature control circuit for the heating device, and a blowing device for nitrogen gas or the like. The reaction conditions are preferably a temperature of 150° C. or higher at which the reaction rate is sufficiently high. To prevent coloring due to oxidation reactions at high temperatures, the temperature should be between 160°C and 210°C.
A range of 0.degree. C. is more preferred. Furthermore, in order to prevent side reactions due to oxidation at high temperatures, it is preferable to carry out the synthesis while passing an inert gas such as nitrogen or carbon dioxide. The reaction proceeds by heating a system in which an acid component and an alcohol component are mixed, and removing low-molecular compounds such as condensed water produced from the system. This is preferably carried out by natural distillation by passing an inert gas, Or by distillation under reduced pressure. Further, if the low molecular weight compound to be distilled has a high boiling point, a high vacuum is required. Furthermore, in order to promote the distillation of low-molecular compounds such as condensed water, a solvent such as toluene or xylene can be added to the system as an azeotropic component to perform natural distillation. The progress of the reaction can generally be determined by measuring the amount of distillate produced by the reaction, quantifying the terminal functional group, and measuring the viscosity of the reaction system. The unsaturated polyester used in the present invention is
It has a molecular weight of 500 to 8,000 per mole of unsaturated group, preferably 1,000 to 4,000 per mole of unsaturated group. Such an unsaturated polyester can be produced by a known method by adjusting the blending ratio of the materials. If the molecular weight per mole of unsaturated groups in the unsaturated polyester is less than 500, the crosslinking density of the cured resin will be high, resulting in a high shrinkage rate of the resin and the cured resin will not be soft. This may cause failure in peeling off from the front glass or cathode ray tube face plate. If the molecular weight per mole of unsaturated groups in the unsaturated polyester exceeds 8,000, sufficient cross-linking will not occur during resin curing, resulting in copolymerization of only styrene and/or its derivatives, resulting in a cured resin. The color becomes cloudy, and the cathode ray tube cannot be used commercially. In addition, since sufficient bridging does not occur, under high temperature and high humidity conditions (85°C, 90%, RH), the adhesive strength with the front glass or cathode ray tube face plate decreases, causing peeling. In the present invention, styrene and/or its derivatives include styrene, p-methylstyrene,
α-methylstyrene, vinyltoluene, divinylbenzene, chlorostyrene, dichlorostyrene, etc. can be used. These can be used alone or in combination. In the present invention, monoesters and/or diesters of unsaturated dibasic acids include monomethyl fumarate, dimethyl fumarate, monomethyl maleate, dimethyl maleate, monoethyl fumarate, diethyl fumarate, monoethyl maleate, diethyl maleate, Monopropyl fumarate, dipropyl fumarate, monopropyl maleate, dipropyl maleate, monobutyl fumarate, dibutyl fumarate, monooctyl fumarate, dioctyl fumarate, monomethyl itaconate, dimethyl itaconate, diethyl itaconate, monoethyl itaconate , monobutyl itaconate, dibutyl itaconate, monopropyl itaconate, dipropyl itaconate, and various other esters can be used. These esters can be used alone or in combination. In the present invention, the number of moles of unsaturated groups in unsaturated polyester is (a), the number of moles of unsaturated groups in styrene and/or its derivatives is (b), monoester of unsaturated dibasic acid and/or Or, when the number of moles of unsaturated groups in the diester is (c), (b)/{(a)+
(c)} is used in a ratio of 1/10 to 10/1 using unsaturated polyester, styrene and/or its derivatives, and monoesters and/or diesters of unsaturated dibasic acids, but (b)/{(a )+(c)} is 1/
A range of 2 to 5/1 is preferred. When the ratio of (b)/{(a)+(c)} is larger than 10/1, curing distortion easily occurs when the unsaturated polyester resin composition of the present invention is cured, and stripes appear on the screen. Patterns and bright spots will appear, detracting from the product's value. On the other hand, if the ratio of (b)/{(a)+(c)} is less than 1/10, the viscosity of the unsaturated polyester resin composition in which maleic anhydride is dissolved will be high, making injection work extremely difficult. This leads to a decrease in workability, such as difficulty in removing bubbles when mixing or pouring the curing agent. Maleic anhydride is used in an amount of 0.5 to 5 parts by weight based on 100 parts by weight of the above unsaturated polyester resin composition. If the amount of maleic anhydride used is less than 0.5 parts by weight, the improvement in adhesion to glass, which is the effect of adding maleic anhydride, will not be achieved, and if it is added in excess of 10 parts by weight, the cured product will become hard. If the cathode ray tube becomes too thick, it becomes impossible to recover it, and part of the maleic anhydride crystallizes and appears as a bright spot. In the present invention, the unsaturated polyester may be dissolved in a mixture of styrene and/or its derivative and a monoester and/or diester of an unsaturated dibasic acid. After dissolving, a monoester and/or diester of an unsaturated dibasic acid may be added. Alternatively, by dissolving an unsaturated polyester in a monoester and/or diester of an unsaturated dibasic acid,
Furthermore, styrene and/or its derivatives may be added. Maleic anhydride is heated in advance to about 54 to 60°C and added as a liquid, but it may also be added to the unsaturated polyester resin and heated to about 54 to 60°C to dissolve it. The unsaturated polyester resin composition for cathode ray tube processing prepared in this way is treated with a polymerization inhibitor such as hydroquinone, pyrocatechol, or 2,6-di-tertiarybutyl para-cresol, if necessary. It can be cured using organic peroxide catalysts such as methyl ethyl ketone peroxide, benzoyl peroxide, cumene hydroperoxide, and lauroyl peroxide. In addition, these organic peroxide catalysts include metal soaps such as cobalt naphthenate and cobalt octenoate, quaternary ammonium salts such as dimethylbensylammonium chloride, β-diketones such as acetylacetone, dimethylaniline, N- It can be used in combination with a curing accelerator such as amines such as ethyl metatoluidine and triethanolamine. In addition, the unsaturated polyester resin composition of the present invention can be used as a photopolymerization initiator, such as diphenyl disulfide, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin-n-propyl ether, benzoin isopropyl ether, benzoin sec-butyl ether,
Photocuring can also be performed using benzoin-2-pentyl ether, benzoin cyclohexyl ether, dimethylbenzyl ketal, or the like. The above organic peroxides and these photopolymerization initiators may be used in combination. The resin composition of the present invention may contain a dye, a plasticizer, an ultraviolet absorber, etc., if necessary. The unsaturated polyester resin composition for cathode ray tube processing according to the present invention is injected between the face plate portion and front glass of cathode ray tubes such as cathode ray tubes for televisions and display tubes for computers, and then hardened. (Example) The present invention will be explained below with reference to Examples. Parts indicate parts by weight. Examples 1 and 2 1166 parts of diethylene glycol, 584 parts of adipic acid, 740 parts of phthalic anhydride, and 116 parts of fumaric acid were charged into a No. 3 four-necked flask equipped with a stirring bar, condenser, nitrogen gas inlet tube, and thermometer, and nitrogen gas was introduced into the flask. The temperature was raised to 150°C in 1.5 hours using a mantle heater while slowly flowing water. Furthermore, the temperature was raised to 200℃ over 4 hours,
It was kept at that temperature. Unsaturated polyester A having an acid value of 34 was obtained in about 10 hours. After further lowering the temperature to 100° C. and adding 1 part of hydroquinone as a polymerization inhibitor, the unsaturated polyester A was poured into a stainless steel vat and left to cool in the air. The resulting unsaturated polyester A had a molecular weight of 2440 per mole of unsaturated groups. This unsaturated polyester A was dissolved in a mixed solution of styrene and dibutyl fumarate according to the formulation shown in Table 1 to obtain an unsaturated polyester resin composition. To this unsaturated polyester resin composition, solid maleic anhydride is added at room temperature so as to have the formulation shown in Table 1, and the whole is heated to 57°C to dissolve it, resulting in a uniform unsaturated polyester resin composition for cathode ray tube processing. I got it. To this were added 0.025 part of cobalt octylate (metal content 6% by weight, manufactured by Dainippon Ink and Chemicals) and 1 part of methyl ethyl ketone peroxide (manufactured by NOF Corporation). On the other hand, on a 3 mm x 250 mm thick transparent flat glass, leave a 3 mm x 250 mm x 250 mm thick silicon plate and cut out the inside with a razor to a size of 240 mm x 240 mm, leaving one spot around the remaining area. A silicone plate with a slit injection port was placed as a spacer. Thickness 3mm x 250mm x on top of this spacer
A 250 mm transparent flat glass plate was placed and the glass plates were fastened with a stopper to obtain a casting jig. The above unsaturated polyester resin composition was injected through the slit inlet of the spacer between the casting jigs. Thereafter, the resin was left in an electric dryer at 80° C. for 90 minutes to harden the resin, thereby obtaining an unsaturated polyester resin cast plate. Table 1 shows the properties of the casting plate thus obtained. As Comparative Examples 1 and 2, compositions having the formulations shown in Table 1 were prepared using the unsaturated polyesters A of Examples 1 and 2, and the characteristics of the casting plates were examined in the same manner. There was no curing distortion during curing in Examples 1 and 2, and no striped patterns or bright spots were observed. However, in Comparative Examples 1 and 2, although no striped patterns or bright spots were observed, peeling occurred when left in an electric dryer at 150° C. for 96 hours, and the adhesive strength was lower than that of Examples 1 and 2.

[Table] In Table 1 (same as Table 2), the curing strain was visually observed, and the presence or absence of striped patterns and the number of bright spots were counted.
Peeling was also visually observed, and its presence or absence was indicated by the area where it occurred. Adhesive strength was determined by adhering two glass plates with a thickness of 10 mm x 40 mm x 40 mm with this unsaturated polyester resin composition by shifting them so that the bonding surfaces were 20 mm x 20 mm (curing conditions: 1% by weight of methyl ethyl ketone peroxide). , cured at 80°C for 5 hours), sandwiched between spacers on both sides and compressive load applied from above and below, and the shear force when the bonded surface was broken was expressed as the value divided by the bonded area. Examples 3, 4, 5 1474 parts of dibropylene glycol, 1241 parts of adipic acid, and 147 parts of maleic anhydride were placed in a four-necked flask (No. 3) equipped with the same equipment as in Example 1, and heated with a mantle heater while slowly flowing nitrogen gas. The temperature was raised to 150°C in 1 hour. Furthermore, the temperature was raised to 200℃ over 4 hours,
It was kept at that temperature. After about 12 hours, unsaturated polyester B having an acid value of 25 was obtained. The temperature was further lowered to 100° C., 1 part of hydroquinone was added as a polymerization inhibitor, and the unsaturated polyester B was poured into a stainless steel vat, left to stand at room temperature, and cooled. The resulting unsaturated polyester B had a molecular weight of 1710 per mole of unsaturated groups. This unsaturated polyester was dissolved in a mixed solution of styrene and diethyl fumarate according to the formulation shown in Table 2, and then maleic anhydride, which had been made into a liquid by heating in advance, was added to obtain an unsaturated polyester resin composition. Table 2 shows the properties of the casting plate obtained by curing this unsaturated polyester resin composition in the same manner as in Examples 1 and 2. No curing distortion was observed in Examples 3, 4, and 5.

【table】

[Table] (Effects of the invention) The unsaturated polyester resin composition for cathode ray tube processing according to the present invention can significantly reduce curing distortion during curing that occurs with conventional resin compositions.
Furthermore, it does not cause cracks, has excellent adhesion to glass plates, and does not peel off. The unsaturated polyester resin composition of the present invention is a suitable resin composition for cathode ray tube processing.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a cathode ray tube. Explanation of symbols, 1...Cathode ray tube, 2...Face plate section, 3...Front glass, 4...Tape,
5...Resin composition.

Claims (1)

[Claims] 1. Per mole of unsaturated groups obtained by reacting an acid component containing an unsaturated dibasic acid and/or its acid anhydride, and optionally other polybasic acid with an alcohol component. An unsaturated polyester having a molecular weight of 500 to 8000 is converted into styrene and/or its derivatives and monoesters and/or diesters of unsaturated dibasic acids, and the number of moles of unsaturated groups in the unsaturated polyester is (a), styrene (b)/ Cathode ray tube treatment containing 100 parts by weight of an unsaturated polyester resin composition dissolved in the range of {(a)+(c)}=1/10 to 10/1 and 0.5 to 10 parts by weight of maleic anhydride. Unsaturated polyester resin composition for use.