JPH0315926B2 - - 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, due to a wide variety of required characteristics, especially dimensional accuracy, demands for low-temperature punching or no-heat punching, and further demands in terms of price 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 or no-heat punching properties. 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. but,
When additive flame retardants are used, the heat resistance of the laminate,
Chemical resistance and electrical properties are reduced, and interlayer adhesion is significantly reduced due to a reduction in crosslinking density of the resin.
In particular, regarding punching properties, delamination between layers, falling powder, 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, especially halogen (in practical use)
The combined use of P (in which Br is frequently used) and P has other advantages as well. In other words, rather than using elements with flame retardant effects (halogen, P, N, B, etc.) alone, when multiple elements are used together, the flame retardant effect increases due to their synergistic effect, resulting in 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 give an example of the most frequently used composite system of Br and P, conventionally, Br-based systems are
As mentioned above, both the additive type and the reactive type have been put into practical use, but for P-based materials, only the additive type has been put into practical use. Therefore, even if it is possible to find a blending ratio that exhibits the optimum flame retardant effect in a composite system of Br and P, 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 a blending system with a high flame retardant effect was necessarily selected. As a result, the amount used to ensure flame retardancy increases, resulting in problems such as a decrease in properties and an increase in cost. The present invention solves the above-mentioned problems of conventional flame retardant resins and flame retardants, exhibits flame retardant effects even when used in small amounts, 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 causing any damage. Means for Solving the Problems The present invention has been made to achieve the above objects, and the first invention is that brominated bisphenol A diglycidyl ether (number of moles of epoxy groups contained a) and general formula [] (However, m = 1 or 2, R ₁ is a carbon number of 1 to
6 alkyl group,

【formula】

[Formula] (p is an integer of 1 to 3, R ₂ is an alkyl group having 1 to 3 carbon atoms),

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

[Formula] (selected from the group of p+r≦5) phosphoric acid esters (number of moles of hydroxyl groups contained b) are reacted in a proportion such that a>b, and then the general formula [] (However, R ₃ is H, an alkyl group having 1 to 3 carbon atoms)
This is a method for producing a flame-retardant resin composition for a laminate, which is characterized by adding and reacting an aromatic amine represented by (number of moles of -NH contained c) such that a-b=c. Further, the second invention provides, in the first invention, instead of the aromatic amine represented by the general formula [], When using an aromatic amine represented by
The third invention is the first invention, in which, in place of the aromatic amine represented by the general formula [], This is the case when using the aromatic amine shown in .
In either case, the amount of conversion is the same as in the first invention. Effect The hydroxyl group of the phosphoric acid ester represented by the general formula [] has 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 relatively freely phosphoricate without exposing the drawbacks of the additive type phosphoric esters. 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. Furthermore, after reacting the brominated bisphenol A diglycidyl ether with the phosphoric acid ester, the aromatic amine represented by the general formula [] or the formula [] or [] is converted into an amine equivalent to the remaining epoxy group. By adding it in a certain amount, it is bonded to the remaining epoxy groups. The aromatic amine represented by the general formula [] or the formula [] or [] is -NH ₂
It retains the ability to be methylolated at the ortho position with respect to the group by formaldehyde, and can easily proceed with bonding with the phenolic resin when it is blended with the phenolic resin and cured. In this way, by combining the entire reaction composition 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. Regarding the usage amount of the phosphoric acid ester represented by the general formula [], when the number of moles of the hydroxyl group b of the phosphoric acid ester is larger than the number of moles of the epoxy group a of the brominated bisphenol A diglycidyl ether,
The remaining hydroxyl groups react with the aromatic amine added later, leaving a low-molecular phosphoric acid ester amine salt in the system, which is undesirable because it incorporates the disadvantages of additive flame retardants. .
Furthermore, 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 brominated bisphenol A diglycidyl ether, the effect on flame retardancy will decrease. Within the above range, as the amount of phosphoric acid ester increases relative to brominated bisphenol A diglycidyl ether, the number of terminals where the reaction ends between the epoxy group and the phosphoric ester increases, and the amount of phosphoric acid ester increases. The flexibility is improved by adding the flexibility effect of ester. Furthermore, the number of epoxy groups that can react with tertiary amines also decreases, so the above-mentioned tendency increases. The number of hydroxyl groups (m=1 or 2) in the phosphoric ester represented by the general formula [] is not particularly limited, and a single structure with m=1 or 2 or a mixture thereof can be used. In the general formula [], when the amount of phosphoric acid ester represented by m=1 increases, the average molecular weight of the reaction system becomes relatively low, and the flexibility improves. Also,
When the amount of phosphoric acid ester used, which is represented by m=2, increases, the average molecular weight of the reaction system increases, and although the flexibility slightly decreases, the interlayer adhesion improves. In addition, phosphoric acid esters that can be used include:
an alkyl phosphate ester in which R ₁ is an alkyl group having 1 to 6 carbon atoms, and R ₁ is a phenyl group, 1
It is a phosphoric acid ester which is a ~3-substituted alkyl (carbon number 1-3) phenyl group, a 1-3 substituted bromo or chlorophenyl group. They can be used as a single structure, a composite of the above structures, or a mixture thereof. In alkyl phosphate esters, as the number of carbon atoms in the alkyl group increases, flexibility improves, but the flame retardant effect tends to decrease. If the number of carbon atoms exceeds 6, the solubility in a phenolic resin solution containing a large amount of methanol decreases, making it unsuitable as a flame-retardant resin for laminates. In the phenyl phosphate ester, the number of carbon atoms of the alkyl group substituted with the phenyl group is also 3 for the same reason as above.
Limited to within 1 month. In addition, Br on the phenyl group
Alternatively, when Cl is substituted, a more significant effect on flame retardancy is exhibited. From the above characteristic trends, the total amount of phosphoric acid ester represented by the general formula [], the number of substituents (m), the structure of substituent R ₁ , and By adjusting their mixing ratio, a flame-retardant resin with predetermined characteristics can be obtained. The reaction system of the brominated bisphenol A diglycidyl ether of the present invention and the phosphoric acid ester represented by the general formula does not require. Since the phosphoric acid ester represented by the general formula [] is a relatively strong acid, if it remains, as mentioned above, the aromatic ester represented by the general formula [] or the formula [], [] added later will be Easily forms acid amides with amines, leaving low molecular weight compounds behind.
However, the reaction can be confirmed by the following method, and it can be proven that most of the phosphoric acid ester has completely reacted with the brominated bisphenol A diglycidyl ether. That is, a certain amount of a mixture of brominated bisphenol A diglycidyl ether and a phosphoric acid ester represented by the general formula [] was taken, diluted with distilled water to a tenfold volume, and after stirring, the PH of the aqueous layer was phase-separated. Measure. Although it depends on the structure and usage amount of the phosphoric ester represented by the general formula [], the pH at the time of blending is 1 to 3, but after the reaction the pH reaches 6.8 to 7.0, so the phosphoric ester is almost completely converted to It is thought that the hydroxyl groups possessed are consumed by the reaction. After their reaction, the general formula [] or formula [],
The aromatic amine shown in [] is added, but -
The ortho position of the NH ₂ group is unsubstituted and has room for reaction with formaldehyde. This allows formaldehyde to undergo methylolization, facilitates bonding with the phenolic resin, and binds the entire reaction system to one of the skeletons of the phenolic resin, thereby suppressing the drawbacks as an additive flame retardant. It is something. The amount of the aromatic amine represented by the general formula [] or the formula [] or [] is the amount of the epoxy remaining after the reaction of the brominated bisphenol A diglycidyl ether in the first stage with the phosphoric acid ester represented by the general formula []. If the number of moles of _-NH2 groups is larger than the number of moles of groups, the storage stability of the blended solution with phenolic resin will deteriorate due to the action of the remaining _-NH2 groups, and in extreme cases, the blended solution will deteriorate. It may become cloudy immediately afterwards. 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 phenolic resin and the coating substrate will deteriorate due to the action of the residual epoxy groups. . Therefore, the general formula [] or formula [],
The amount of aromatic amine to be added, represented by [], is determined by the number of moles of -NH ₂ groups contained, and the amount remaining after the reaction between the brominated bisphenol A diglycidyl ether in the first stage and the phosphoric acid ester represented by general formula []. It is preferable to make the number of moles of epoxy groups equal and to allow the epoxy groups and -NH ₂ groups to react completely. The flame retardant resin of the present invention can be used alone or with a relatively small amount of triphenyl phosphate,
It is also possible to use an additive type flame retardant such as 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
1532g of toluene solution and formula and expression Phosphate ester represented by (weight ratio A/B=1/
1) 73g was put into a three-necked flask and reacted at 80°C for 2 hours (Reactant 1). 5 g of the solution at the time of blending and at the end of the reaction was collected, distilled water was added to make the total amount 50 g, and after stirring, the pH of the aqueous phase separated was measured and found to be 2.3 and 7.0, respectively. Further, when the epoxy equivalent was measured by the tetraethylammonium bromide-perchloric acid method, the epoxy equivalent weight of the entire solution was 1020 and 700 at the time of blending and after completion of the reaction, respectively. Subsequently, the expression

Add 78g of the aromatic amine represented by the formula and further heat the mixture at 80℃ for 1 hour.
The reaction was carried out for a period of time (Reactant 2). 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 further advanced at 80°C, and when the curing time on a 160°C hot plate reached 6 minutes, the mixture was dehydrated and concentrated, and methanol was then added to adjust the resin content to 50%. This tung oil modified phenolic resin and the reactant 2 were mixed and dissolved at a solid content ratio of 80/20, and this varnish was mixed with 11
It was coated on Mils kraft paper with a resin adhesion of 50% and dried. One sheet of 35μ 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 1532 g of brominated bisphenol A diglycidyl ether toluene solution similar to Example 1 and the formula

【formula】 and expression

[Formula] Phosphate ester (weight ratio C/D=1/
1) Pour 97g into a three-necked flask, react in the same manner as in Example 1, and after confirming the pH, form the formula

96g of aromatic amine represented by [Formula] was added and reacted in the same manner as in Example 1 (Reactant 3) Furthermore, a varnish was prepared by mixing Reactant 3 and tung oil-modified phenolic resin in the same ratio as in Example 1. 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 3 Formula

【formula】 as well as formula

[Formula] Phosphate ester (weight ratio E/F=1/
1) is 107g, formula

A 1.6 mm thick one-sided copper-clad paper-based phenolic resin laminate was obtained in the same manner as in Example 1 except that 77 g of the aromatic amine represented by the formula was used. Example 4 Formula

【formula】 as well as formula

[Formula] Phosphate ester (weight ratio G/H=1/
1) 534g, formula

Using 36 g of the aromatic amine represented by the formula, a 1.6 mm thick one-sided copper-clad paper-based phenolic resin laminate 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 obtain a thickness of 1.6 in the same manner as in Example 1.
A phenolic resin laminate with a copper-clad paper substrate on one side of mm was obtained. Comparative Example 2 The tung oil-modified phenolic resin used in Example 1 and the brominated bisphenol A diglycidyl ether and triphenyl phosphate used in Comparative Example 1 were mixed in a solid content ratio of tung oil-modified phenolic resin/brominated bisphenol A diglycidyl ether and triphenyl phosphate used in Comparative Example 1. Glycidyl ether/triphenyl phosphate was mixed and dissolved in a ratio of 60/30/10, and using this varnish, a 1.6 mm thick single-sided copper-clad paper base phenolic resin laminate was obtained in the same manner as in Example 1. Ta. The test results of the laminates obtained in Examples and Comparative Examples were
Shown in the table.

[Table] Effects of the Invention The above test results show that the present invention can reduce the amount of flame retardant used and improve the low-temperature punching properties 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)

[Scope of Claims] 1 Brominated bisphenol A diglycidyl ether (number of moles of epoxy groups contained a) and general formula [] (However, m = 1 or 2, R ₁ is a carbon number of 1 to
6 alkyl group, [Formula] [Formula] (p is an integer of 1 to 3, R ₂ is an alkyl group having 1 to 3 carbon atoms), [Formula] (r is an integer of 1 to 3, X is Cl or Br ),
[Formula] (selected from the group of p+r≦5) phosphoric acid esters (number of moles of hydroxyl groups contained b) are reacted in a proportion such that a>b, and then the general formula [] (However, R ₃ is H, an alkyl group having 1 to 3 carbon atoms)
1. A method for producing a flame-retardant resin composition for a laminate, which comprises adding and reacting an aromatic amine represented by (the number of moles of -NH contained, c) such that a-b=c. 2 Brominated bisphenol A diglycidyl ether (number of moles of epoxy groups contained a) and general formula [] (However, m = 1 or 2, R ₁ is a carbon number of 1 to
6 alkyl group, [Formula] [Formula] (p is an integer of 1 to 3, R ₂ is an alkyl group having 1 to 3 carbon atoms), [Formula] (r is an integer of 1 to 3, X is Cl or Br ),
[Formula] (selected from the group of p+r≦5)) Phosphate ester (containing mole number of hydroxyl groups b) is reacted in a proportion such that a>b, and then the formula [] 1. A method for producing a flame-retardant resin composition for a laminate, which comprises adding and reacting an aromatic amine represented by (the number of moles of -NH contained, c) such that a-b=c. 3 Brominated bisphenol A diglycidyl ether (number of moles of epoxy groups contained a) and general formula [] (However, m = 1 or 2, R ₁ is a carbon number of 1 to
6 alkyl group, [Formula] [Formula] (p is an integer of 1 to 3, R ₂ is an alkyl group having 1 to 3 carbon atoms), [Formula] (r is an integer of 1 to 3, X is Cl or Br ),
[Formula] (selected from the group of p+r≦5)) Phosphate ester (containing mole number of hydroxyl groups b) is reacted in a proportion such that a>b, and then the formula [] 1. A method for producing a flame-retardant resin composition for a laminate, which comprises adding and reacting an aromatic amine represented by (the number of moles of -NH contained, c) such that a-b=c.