JPH0334770B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a method for producing a flame-retardant resin composition for laminates that has excellent flame retardancy, flexibility, low-temperature punchability, and storage stability. BACKGROUND OF THE INVENTION In recent years, from the standpoint of the safety of household electrical appliances, there has been an increasing demand for flame retardant printed circuit boards used therein. At the same time, there are a wide variety of required characteristics, especially dimensional accuracy requirements, demands for low-temperature punching performance or no-heat punching performance, and even price requirements are becoming stricter year by year. Therefore, there is a need for a flame-retardant resin for laminates that is low-cost, has little property deterioration, and has excellent low-temperature punching properties and no-heat punching properties, but conventional flame-retardant resins or flame retardants are not completely effective. It was difficult to satisfy the above objectives. That is, as conventional flame retardant resins and flame retardants, there are known low molecular weight additive flame retardants that do not have reactivity and reactive flame retardants that have reactivity. When an additive flame retardant is used, the heat resistance, chemical resistance, and electrical properties are reduced, and furthermore, the interlayer adhesion of the laminate is significantly reduced due to a reduction in the crosslinking density of the resin. In particular, regarding punchability, delamination between layers, powder falling, and clogging of the die hole occur during punching. On the other hand, when reactive flame retardants are used, although the above-mentioned drawbacks are small, the increased crosslink density when formed into a laminate moves the softening point of the laminate to a higher temperature side, making it easier to punch at low temperatures or without heating. Moreover, since the reactivity is high, the storage stability of the compounded resin and the coating base material becomes poor. As representative examples of the former, brominated bisphenol A, brominated diphenyl ether, triphenyl phosphate, and their alkyl derivatives have been put into practical use. A typical example of the latter is brominated epoxy resin. In reality, both are used in combination, taking into consideration their respective strengths and weaknesses, due to a wide variety of requirements for characteristics. In addition, the combination of both, particularly the combination of halogen (Br is often used in practice) and P, has advantages from other aspects as well. In other words, the flame retardant effect increases due to their mutual effect when multiple elements that have a flame retardant effect (halogen, P, N, B, etc.) are used in combination than when used alone. As a result, the total amount of flame retardant resin and flame retardant used can be reduced. Furthermore, since the additive flame retardant has an excellent plasticizing effect, when used in combination, flexibility and punchability can be improved. However, to take an example of the most frequently used composite system of Br and P, as mentioned above, both additive and reactive flame retardants have been put into practical use for conventional Br-based flame retardants, but P-based Only additive flame retardants have been put into practical use. Therefore, Br and P
Even if it were possible to find a blending ratio that provides the optimum flame retardant effect in a composite system, the amount used cannot be easily increased due to the disadvantages of additive flame retardants. Problems to be Solved by the Invention Due to various limitations in the properties of conventional flame retardant resins and flame retardants, it is difficult to freely change the ratio of halogen, P, N, etc. to obtain the optimal flame retardant effect. The degree of flame retardancy was very narrow, and it could not be said that the blending system with the highest flame retardant effect was necessarily selected. In addition, from the standpoint of flexibility and low-temperature punching, the amount of additive type used is limited, and conventional flame-retardant resins are based on reactive types, which reduces flexibility and makes it difficult to use for low-temperature punching. was not appropriate. As a result, the amount used to ensure flame retardancy has increased, resulting in problems such as deterioration of low-temperature punchability and other properties, and increased cost. The present invention solves the above-mentioned problems of conventional flame retardant resins and flame retardants, exhibits a flame retardant effect even when used in small amounts, and has excellent flame retardancy and reduces other properties. It is an object of the present invention to provide a flame-retardant resin composition for laminates that has excellent flexibility, low-temperature or non-heat punching properties, and storage stability without any problems. Means for Solving the Problems The present invention has been made to achieve the above objects, and the first invention is based on brominated bisphenol A diglycidyl ether and the general formula [] (R ₁ and R ₂ are −CH ₂ −, −C ₂ H ₄ −,

After reacting a brominated bisphenol A alkyl oxide adduct diglycidyl ether selected from [Formula] and represented by m, n = an integer of 1 to 6) using a tertiary amine as a catalyst, the general formula [] (R ₃ is an alkyl group having 1 to 6 carbon atoms,

【formula】

[Formula] (p = an integer of 1 to 3, R ₄ is an alkyl group having 1 to 3 carbon atoms),

[Formula] (r = integer from 1 to 3, X is Cl Ruiha Br),

A phosphoric acid ester represented by the formula (p+r≦5) is added and reacted. At this time, the amount of phosphoric acid ester added is such that the number of moles of hydroxyl groups contained is smaller than the number of moles of epoxy groups remaining after the reaction of the former two. And furthermore, general formula [] (R ₅ is selected from H and an alkyl group having 1 to 3 carbon atoms) is added and reacted. The amount of the aromatic amine added is such that the number of moles of the -NH group contained is equal to the number of moles of the epoxy group remaining after the reaction of the brominated bisphenol A diglycidyl ether, general formula [] and []. do. Further, the second invention provides, in place of the aromatic amine represented by the general formula [] in the first invention,
formula〔〕 When using the aromatic amine shown in
The third invention is based on the general formula [ ] in the first invention.
In place of the aromatic amine represented by the formula [] This is the case when an aromatic amine represented by is used. Effect By using together brominated bisphenol A diglycidyl ether and brominated bisphenol A alkyl oxide adduct diglycidyl ether represented by the general formula [], flexibility is imparted by the alkyl oxide structure of the latter, making it more flexible than conventional Reactive flame retardant with excellent flexibility by exhibiting flexibility that was insufficient in brominated bisphenol A diglycidyl ether, and by leaving an epoxy group, which is a reactive group, at the end of the reactive molecule. Resin can be obtained. At the same time, introducing an alkyl oxide group into the molecular skeleton widens the spacing of the bromine-substituted bisphenol A structure by the flexible alkyl oxide group, which suppresses crystallization and improves storage stability. improves. The mixing ratio of brominated bisphenol A diglycidyl ether and brominated bisphenol A alkyl oxide adduct diglycidyl ether represented by the general formula [] is not particularly limited; In order to exhibit an effect on the latter, it is desirable that the latter be 5 parts by weight or more per 100 parts by weight of the former. As the latter increases, flexibility and storage stability improve, so it may be used alone. However, since the Br content is slightly lower than the former, it is better to adjust the mixing ratio of the two depending on the application system in order to obtain a predetermined flame retardant effect. In the general formula [], when R ₁ and R ₂ have 4 or more carbon atoms, the heat resistance is slightly lowered and the compatibility with methanol-rich phenolic resins is also lowered. Catalysts that can be used are tertiary amines such as trimethylamine, triethylamine, triethanolamine, benzyldimethylamine. first,
When a secondary amine is used, a three-dimensional crosslinked structure is likely to be formed, resulting in loss of compatibility with the phenolic resin. The amount of catalyst added is brominated bisphenol A diglycidyl ether and general formula []
0.05-5% based on the solid weight of the compound represented by
A range of is desirable. The hydroxyl group of the phosphoric acid ester represented by the general formula [] has a very high reactivity with the epoxy group, and reacts in a short time even without a catalyst when heated to 40 to 50°C or higher. Due to this reactivity, the phosphoric acid ester binds to the brominated epoxy resin which has been polymerized to some extent, so it can be relatively freely oxidized without exposing the drawbacks of the additive-type phosphoric esters mentioned above. It is possible to increase the amount of ester used. In this way, the mutual effect of Br and P can be increased to the point where it can be effectively exerted. Regarding the usage amount of the phosphoric acid ester represented by the general formula [], the amount of epoxy remaining after the reaction between the brominated bisphenol A diglycidyl ether and the brominated bisphenol A alkyl oxide adduct diglycidyl ether represented by the general formula [] It is necessary that the number of moles of hydroxyl groups in the phosphate ester is smaller than the number of moles of groups. In other words, if the number of hydroxyl groups in the latter is greater than the number of epoxy groups in the former, it will react with the aromatic amine added later, leaving a low-molecular-weight phosphoric acid ester amine salt in the system. This is not preferable because the disadvantages of type flame retardants are inherent. The amount of phosphoric acid ester used is not particularly limited within the above range, but if the amount of P contained in the phosphoric acid ester is less than 2% with respect to the amount of Br contained in the reactant in the first stage, flame retardancy is observed. The effect on As the amount of phosphoric acid ester used increases within the above range, the number of ends where the reaction ends between the epoxy group and the phosphoric acid ester increases, and the flexibility effect of the phosphoric acid ester is added, resulting in increased flexibility. will improve. From the above, the amount of phosphoric acid ester to be used can be appropriately selected depending on the desired flame retardant effect and flexibility effect of the applied system. The number of hydroxyl groups (l=1 or 2) in the phosphoric ester represented by the general formula [] is not particularly limited, and a single structure with l=1 or 2 or a mixture thereof can be used. In the general formula [], when the amount of the phosphoric acid ester represented by m=1 increases, the average molecular weight of the reaction system increases and the flexibility slightly decreases, but the interlayer adhesion improves. In addition, phosphoric acid esters that can be used include:
R ₃ is an alkyl phosphate ester having 1 to 6 carbon atoms,
Further, there are phosphoric acid esters in which R ₃ is a phenyl group, a 1- to 3-substituted alkyl (carbon number 1-3) phenyl group, or a 1- to 3-substituted bromo or chlorophenyl group. They can also be used as single structures, composites of the above structures, or mixtures thereof. In alkyl phosphate esters, when the number of carbon atoms in the alkyl group exceeds 6, flexibility improves, but heat resistance tends to decrease, and it is difficult to dissolve in phenolic resin solutions containing a large amount of methanol. It is unsuitable as a flame retardant resin for laminates because of its reduced properties. In the phenyl phosphate ester, the number of carbon atoms in the alkyl group substituted by the phenyl group is preferably 3 or less for the same reason as described above. Further, when the phenyl group is substituted with Br or Cl, a more remarkable effect on flame retardancy is exhibited. From the above characteristic trends, brominated bisphenol A alkyl oxide adduct diglycidyl ether represented by the general formula [] and phosphate ester represented by the general formula [] By selecting the total amount used, and the structure, number, and mixing ratio of substituents, a flame-retardant resin with predetermined characteristics can be obtained. Furthermore, after the above-mentioned three reactions, an aromatic amine represented by the general formula [] or the formula [] or [] is added to react with the epoxy group remaining in the reaction system so as to have the same amine equivalent. The remaining epoxy group is bonded to the remaining epoxy group. The aromatic amine represented by the general formula [] or the formula [], [] is -
It retains the ability to be methylolated at the ortho position with respect to the NH ₂ group by formaldehyde, so it can be blended with a phenolic resin to facilitate bonding with the phenolic resin during curing. In this way, by combining the entire reactive composition of the present invention with the phenolic resin as the main ingredient, it is possible to completely overcome the drawbacks similar to additive flame retardant resins and flame retardants. The added amount of the aromatic amine represented by the general formula [] or [], [] is the former brominated bisphenol A diglycidyl ether and the general formula [],
When the number of moles of -NH group is larger than the number of moles of epoxy group remaining after the reaction of the compound shown in [], due to the action of the remaining -NH group,
The storage stability of a blended solution with a phenolic resin deteriorates, and in extreme cases, it may become cloudy immediately after blending. Furthermore, if the amount of aromatic amine added is small compared to the residual epoxy groups, the storage stability of the mixed solution with the phenol resin and the coated substrate will deteriorate due to the action of the residual epoxy groups.
Therefore, the added amount of the aromatic amine represented by the general formula [] or the formula [], [] is -
The number of moles of the NH group and the number of moles of the epoxy group remaining after the reaction of the brominated bisphenol A diglycidyl ether in the first stage with the general formula [], and further the reaction with the phosphoric acid ester represented by the general formula [] It is preferable to make them equal and allow the epoxy group and -NH group to react completely. The flame retardant resin of the present invention can be used alone or in combination with a relatively small amount of additive flame retardant such as triphenyl phosphate brominated diphenyl ether, but in either case. The total amount of flame retardant resin and flame retardant used can be reduced. Examples Next, examples of the present invention will be described. Example 1 60% of brominated bisphenol A diglycidyl ether with bromine content of 48% and epoxy equivalent weight of 400
920g of toluene solution and formula [a] 613 g of a 60% toluene solution of diglycidyl ether represented by the formula and 2.76 g of dimethylbenzylamine were charged into a three-necked flask and reacted at 90°C for 3 hours (reaction A). Furthermore, formula [b] and formula [c] Phosphate ester represented by (weight ratio b/c=1/
1) 73g was added and reacted at 80°C for 2 hours (Reaction B). After the completion of reaction B, collect 5g of the reaction solution and make the total amount 50
Distilled water was added to give a pH of 7.0 g, and after stirring, the pH of the phase-separated aqueous layer was measured to be 7.0. Furthermore, the epoxy equivalent of the solution as a whole was 1400 when measured by the tetramethylammonium bromide monoperchloric acid method. Subsequently, the expression Add 57g of aromatic amine shown as
The reaction was carried out at ℃ for 1 hour (reaction C) (reactant (1)). Additionally, a tung oil-modified phenol resin was separately obtained as follows. 720 g of tung oil, 580 g of m-cresol, and 0.74 g of para-toluenesulfonic acid in a three-necked flask.
After reacting at 80℃ for 1 hour, phenol 500
g, 86% paraform 450g, 25% ammonia water 35g
The reaction was proceeded at 80°C, and when the curing time on a 160°C hot plate reached 6 minutes, the mixture was dehydrated and concentrated. Methanol was then added to adjust the resin content to 50%. This tung oil modified phenolic resin and the above reactant (1) were mixed in a solid content ratio of tung oil modified phenolic resin/reactant.
(1) Mix and dissolve at a ratio of 80/20, and add 11% of this varnish.
It was coated on Mils kraft paper with a resin adhesion of 50% and dried. One sheet of 35 μ thick copper foil with adhesive and eight sheets of the coated dry paper substrate were combined and heated and pressed to obtain a 1.6 mm thick one-sided copper-clad paper substrate phenolic resin laminate. Example 2 1380 g of brominated bisphenol A diglycidyl ether toluene solution similar to Example 1 and formula [d] 153 g of a 60% toluene solution of diglycidyl ether shown by and 1.84 g of triethylamine were charged into a three-necked flask and reacted at 90°C for 3 hours. Furthermore, the formula [e] and formula [f] Phosphate ester represented by (weight ratio e/f=1/
1) 97g was added and reacted at 80°C for 2 hours. After confirming the PH and epoxy equivalent in the same manner as in Example 1, the formula

70g of aromatic amine represented by the formula was added and reacted at 80°C for 1 hour (reactant (2)). Reactant (1) was used in the same ratio as in the example, and the thickness
A 1.6 mm single-sided copper-clad paper-based phenolic resin laminate was obtained. Example 3 613 g of brominated bisphenol A diglycidyl ether toluene solution similar to Example 1 and formula [g] 920 g of diglycidyl ether shown by and 4.60 g of triethanolamine were charged into a three-necked flask and reacted at 90°C for 3 hours. Furthermore, the formula [h] and formula [i] Phosphate ester represented by (weight ratio h/i=1/
107g of 1) was added and reacted at 80°C for 2 hours. After confirming the PH and epoxy equivalent in the same manner as in Example 1, the formula

50g of aromatic amine represented by the formula was added and reacted at 80°C for 1 hour (reactant (3)). Using the reaction product (3), a 1.6 mm thick one-sided copper-clad paper base phenolic resin laminate was obtained in the same manner as in Example 1. Example 4 153 g of brominated bisphenol A diglycidyl ether toluene solution similar to Example 1 and formula [j] 1379 g of a 60% toluene solution of diglycidyl ether shown by and 9.20 g of dimethylbenzylamine were charged into a three-necked flask and reacted at 90°C for 3 hours. Furthermore, the formula [k] and formula [l] Phosphate ester represented by (weight ratio k/1=1/
1) 534g was added and reacted at 80°C for 2 hours. After confirming the pH and epoxy equivalent in the same manner as in Example 1, the formula

25 g of aromatic amine represented by the formula was added and reacted at 80°C for 1 hour (reactant (4)). Using the reaction product (4), a phenolic resin laminate having a thickness of 1.6 mm and having a copper-clad paper base on one side was obtained in the same manner as in Example 1. Comparative Example 1 A 60% toluene solution of the tung oil modified phenolic resin used in Example 1 and brominated bisphenol A diglycidyl ether with a bromine content of 48% and an epoxy equivalent of 400 was mixed at a solid content ratio of tung oil modified phenolic resin/brominated. Mix and dissolve bisphenol A diglycidyl ether in a ratio of 80/20, and use this varnish to form a layer of 1.6 mm in thickness in the same manner as in Example 1.
A phenolic resin laminate with a single-sided copper-clad paper base was obtained. Comparative Example 2 Tung oil modified phenolic resin used in Example 1, brominated bisphenol A diglycidyl ether used in Comparative Example 1, and triphenyl phosphate in solid content ratio, tung oil modified phenolic resin/brominated bisphenol A Diglycidyl ether/
Triphenyl phosphate was mixed and dissolved in a ratio of 60/30/10, and using this varnish, a 1.6 mm thick one-sided copper-clad paper base phenolic resin laminate was obtained in the same manner as in Example 1. The test results of the laminates obtained in Examples and Comparative Examples were
Shown in the table.

[Table] Effects of the Invention From the above test results, the present invention can reduce the amount of flame retardant used and improve the low-temperature punchability of the laminate. Furthermore, the storage stability of the flame retardant resin solution and coating substrate is improved, and its industrial value is extremely large.

Claims (1)

[Claims] 1. Brominated bisphenol A diglycidyl ether and general formula [] (R ₁ and R ₂ are −CH ₂ , −C ₂ H ₄ ⁻ ,
After reacting a brominated bisphenol A alkyl oxide adduct diglycidyl ether selected from [Formula] and represented by m, n = an integer of 1 to 6) using a tertiary amine as a catalyst, the general formula [] (R ₃ is an alkyl group having 1 to 6 carbon atoms,
[Formula] [Formula] (p = an integer of 1 to 3, R ₄ is an alkyl group having 1 to 3 carbon atoms),
[Formula] (r = an integer of 1 to 3, X is Cl or Br), [Formula] (p+r≦5) is added so that the number of moles of epoxy groups remaining after the reaction of the former two is smaller than the number of moles of epoxy groups remaining after the reaction, and then the general formula [] (R ₅ is selected from H and an alkyl group having 1 to 3 carbon atoms), the number of moles of -NH groups contained in the aromatic amine is A method for producing a flame-retardant resin composition for a laminate, which comprises adding and reacting the three members of general formula [] and [] in an amount equal to the number of moles of epoxy groups remaining after the reaction. 2 Brominated bisphenol A diglycidyl ether and general formula [] (R ₁ and R ₂ are −CH ₂ , −C ₂ H ₄ −,
After reacting a brominated bisphenol A alkyl oxide adduct diglycidyl ether selected from [Formula] and represented by m, n = an integer of 1 to 6) using a tertiary amine as a catalyst, the general formula [] (R ₃ is an alkyl group having 1 to 6 carbon atoms,
[Formula] [Formula] (p = an integer of 1 to 3, R ₄ is an alkyl group having 1 to 3 carbon atoms),
[Formula] (r = an integer of 1 to 3, X is Cl or Br), [Formula] (p+r≦5) is added and reacted in such a way that the number of moles of epoxy groups remaining after the reaction of the first two is smaller, and then the formula [] The number of moles of -NH groups contained in the aromatic amine is determined by the amount of epoxy groups remaining after the reaction of the above-mentioned brominated bisphenol A diglycidyl ether, the general formulas [] and [], 1. A method for producing a flame-retardant resin composition for a laminate, which comprises adding and reacting the composition in an amount equal to the number of moles. 3 Brominated bisphenol A diglycidyl ether and general formula [] (R ₁ and R ₂ are −CH ₂ −, C ₂ H ₄ −,
After reacting a brominated bisphenol A alkyl oxide adduct diglycidyl ether selected from [Formula] and represented by m, n = an integer of 1 to 6) using a tertiary amine as a catalyst, the general formula [] (R ₃ is an alkyl group having 1 to 6 carbon atoms [Formula] [Formula] (p = an integer of 1 to 3, R ₄ is an alkyl group having 1 to 3 carbon atoms),
[Formula] (r = an integer of 1 to 3, X is Cl or Br), [Formula] (p+r≦5) is added and reacted in such a way that the number of moles of epoxy groups remaining after the reaction of the first two is smaller, and then the formula [] The number of moles of -NH groups contained in the aromatic amine is determined by the amount of epoxy groups remaining after the reaction of the above-mentioned brominated bisphenol A diglycidyl ether, the general formulas [] and [], 1. A method for producing a flame-retardant resin composition for a laminate, which comprises adding and reacting the composition in an amount equal to the number of moles.