A novel flame retardant composition for use in prepreg laminates

Abstract

The application discloses a novel flame retardant composition applied to prepreg laminates, which comprises the following components: 5-60 parts of a reactive phosphorus-nitrogen flame retardant, 3-45 parts of a DOPO derivative flame retardant and 20-80 parts of a thermosetting polyphenyl ether resin. The halogen-free additive flame retardant is combined with the reactive flame retardant, the additive flame retardant has good flame-retardant effect, the matrix high polymer resin has poor compatibility, the interface bonding force is poor, and the peeling strength is reduced; the reactive flame retardant is added to the system in the high polymer processing process, and the groups on the flame retardant react with the groups on the high polymer chain under the action of the late processing condition to become part of the high polymer chain, so that the compatibility is good. The halogen-free additive flame retardant is combined with the reactive flame retardant to play a synergistic effect, and the flame-retardant effect is better improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laminated board preparation, in particular to a novel flame retardant composition applied to prepreg laminated board. BACKGROUND

[0002] CN104774476B provides a phosphorus-containing flame-retardant composition, which uses hypophosphite compounds, DOPO derivatives and polyphosphazene compounds to play a synergistic effect among the phosphorus-containing compounds. The composition can achieve halogen-free flame retardation at a low addition amount, can maintain good dielectric properties and heat resistance, but its dielectric properties are relatively poor, which limits its application in high-speed high-frequency copper-clad plates.

[0003] CN113698738A provides a flame-retardant copper-clad plate and a preparation method thereof, which has high-efficiency flame retardancy, thermal stability and heat resistance. Epoxy resin is selected as the main resin, and bromine-based and phosphorus-based flame retardants are used in combination to enhance the flame retardancy of the epoxy resin. The epoxy resin is a thermosetting resin, and a curing agent is needed to make it into an interlinked network structure. Dicyandiamide is selected as the curing agent, and 2-ethyl-4-methyl imidazole is selected as the accelerator to reduce production cost. The preparation of the composite flame retardant effectively improves the flame retardant performance of the copper-clad plate, but still uses halogen-containing flame retardants, which decomposes a large amount of smoke and corrosive gas, limits the improvement space of the material in heat resistance, and also pollutes the environment.

[0004] CN113105498A provides a halogen-free silicon-based flame-retardant allyl compound, a preparation method thereof and an application thereof in copper-clad plates. The halogen-free silicon-based flame-retardant allyl compound can crosslink with bismaleimide resin, thereby solving the problems of high curing reaction temperature of bismaleimide resin, brittleness of the cured resin, poor solubility, and increased polarity of diallyl bisphenol A modified BMI resin. The halogen-free silicon-based flame-retardant allyl compound contains silicon elements, which endows bismaleimide resin with halogen-free flame retardant properties. However, the preparation process is complex, the cost is high, and the dielectric properties are relatively poor.

[0005] The flame retardation of high molecular material is generally achieved by adding flame retardant. At present, the flame retardant includes two categories of additive type flame retardant and reaction type flame retardant. The additive type flame retardant is added into the high molecular material by blending method, so as to prepare the high molecular material with flame retardation, such as the method for preparing the flame-retardant polyolefin cable material by using magnesium hydroxide as the flame retardant disclosed in Chinese patent CN101712875B. This kind of flame retardant adding method causes the poor compatibility of the flame retardant with the base high molecular resin, the poor interfacial bonding force, the need of large amount of addition, the slow precipitation of the additive type flame retardant to the surface of the high molecular material, the reduction of the flame retardation effect, and the deterioration of the material performance; the reaction type flame retardant is added into the reaction system as the monomer during the synthesis of the high molecular material, and finally becomes a part of the high molecular chain through the chemical bond, so as to achieve the effect of persistent flame retardation. The reaction type flame retardant can also be added into the system during the processing of the high molecular material, and the groups on the flame retardant react with the groups on the high molecular chain under the action of the late processing condition, so as to become a part of the high molecular chain, and also achieve the effect of persistent flame retardation. For example, Chinese patent CN112442071A discloses a reaction type flame retardant containing phosphorus. The flame retardant has hydroxyl and alkenyl groups as active sites, and is added into the material or becomes a part of the high molecular polymer as the reaction monomer, so as to achieve the purpose of flame retardation. SUMMARY

[0006] In order to overcome the above-mentioned defects existing in the prior art, the purpose of the present application is to provide a novel flame retardant composition applied to a prepreg laminate.

[0007] The halogen-free additive type flame retardant and the reaction type flame retardant are used in combination in the present application. The additive type flame retardant has good flame retardation effect, poor compatibility with the base high molecular resin, poor interfacial bonding force, and reduced peeling strength; the reaction type flame retardant is added into the system during the processing of the high molecular material, and the groups on the flame retardant react with the groups on the high molecular chain under the action of the late processing condition, so as to become a part of the high molecular chain and have good compatibility. The halogen-free additive type flame retardant and the reaction type flame retardant are used in combination to play a synergistic effect, and better improve the flame retardation effect.

[0008] In order to achieve the purpose of the present application, the technical scheme adopted is as follows:

[0009] A novel flame retardant composition applied to a prepreg laminate, comprising:

[0010] 5-60 parts of reaction type phosphorus-nitrogen flame retardant;

[0011] 3-45 parts of DOPO derivative flame retardant;

[0012] 20-80 parts of thermosetting polyphenyl ether resin;

[0013] The reaction type phosphorus-nitrogen flame retardant has the structure shown in the following formula 1:

[0014]

[0015] Formula 1;

[0016] The R1, R2, R3, R4, R5, R6 are optionally selected from any one of the following structural formulas 2-6;

[0017]

[0018] Formula 2;

[0019]

[0020] Formula 3;

[0021]

[0022] Formula 4;

[0023]

[0024] Formula 5;

[0025]

[0026] Formula 6;

[0027]

[0028] Formula 7;

[0029] The m is an integer of 1-50, X1, X2, X3 are each independently selected from a hydrocarbon group having a carbon atom number of 1-15, and A is a phenyl group or a hydrocarbon group having a carbon atom number of 1-20;

[0030] The structure of the DOPO derivative flame retardant is shown in the following formula 8:

[0031]

[0032] Formula 8;

[0033] The z in the formula 8 is a structure shown in the following formulas 9-12:

[0034]

[0035] Formula 9;

[0036]

[0037] Formula 10;

[0038]

[0039] Formula 11;

[0040]

[0041] Formula 12;

[0042] The thermosetting polyphenyl ether resin is a modified thermosetting polyphenyl ether resin, preferably an ethylene group modified thermosetting polyphenyl ether resin.

[0043] In a preferred embodiment of the present application, the phosphorus content of the reaction type phosphorus-nitrogen flame retardant is 3-30%, further preferably 8-20%; the nitrogen content is 1-15%, further preferably 3-10%.

[0044] In a preferred embodiment of the present application, the number average molecular weight Mn of the reaction type phosphorus-nitrogen flame retardant is 300-10000 g / mol, further preferably 500-5000 g / mol.

[0045] In a preferred embodiment of the present application, the modified thermosetting polyphenyl ether resin is a methacrylate group modified thermosetting polyphenyl ether resin, and the number average molecular weight of the methacrylate group modified thermosetting polyphenyl ether resin is 300-13000 g / mol, preferably 800-5500 g / mol, further preferably 1000-3200 g / mol.

[0046] The present application has the following beneficial effects:

[0047] The halogen-free additive type flame retardant is used in combination with the reaction type flame retardant, the additive type flame retardant has good flame retardant effect, but poor compatibility with the matrix polymer resin, poor interfacial bonding force, and reduced peeling strength; the reaction type flame retardant is added to the system during polymer processing, and the groups on the flame retardant react with the groups on the polymer chain under the action of the later processing conditions to become part of the polymer chain, and the compatibility is good. The halogen-free additive type flame retardant and the reaction type flame retardant are used in combination to play a synergistic effect, and the flame retardant effect is better improved. DETAILED DESCRIPTION

[0048] The present application is further described below by examples, but these examples shall not be used to explain the limitation of the present application.

[0049] Polyphenyl ether:

[0050] SA9000: Sabic methyl methacrylate-terminated polyphenyl ether resin;

[0051] Silane coupling agent: KBM-503, a methyl methacrylate-based silane coupling agent from Japan Shin-Etsu;

[0052] Initiator: azobisisobutyronitrile;

[0053] Co-crosslinking agent

[0054] BMI-70: K.I. Japan (3-ethyl-5-methyl-4-maleimide phenyl) methane;

[0055] B2000: DuPont Japan;

[0056] Flame retardant:

[0057] SPB-100, Otsuka Japan;

[0058] SPV-100: Otsuka Japan;

[0059] OP935: Clariant;

[0060] SPX-200: Daiba;

[0061] PQ60: Jin Yi Chemical, Taiwan, China;

[0062] Filler: inorganic filler, silica powder;

[0063] Glass cloth: 2116E-Glass of E-Glass AST Company;

[0064] Copper foil: King's RG311 1oz.

[0065] Example 1:

[0066] According to the formula, 50 parts by weight of methyl methacrylate-terminated polyphenyl ether resin, 10 parts by weight of bismaleimide, 20 parts by weight of styrene-butadiene copolymer, 20 parts by weight of co-crosslinking agent, 40 parts by weight of crosslinking agent, 1.5 parts by weight of free radical initiator, 2.0 parts by weight of methacrylate silane coupling agent, 40 parts by weight of phosphorus-based flame retardant, 30 parts of additive flame retardant, 100 parts by weight of silica powder, were dissolved in toluene solvent.

[0067] 2. Sizing, to make prepreg;

[0068] a. The adhesive is circulated to the sizing machine, and the adhesive is evenly coated on the glass fiber cloth through pre-impregnation and main impregnation. The line speed control of the sizing machine is 15 m / min;

[0069] b. The glass fiber cloth coated with adhesive is baked in a 130°C drying oven to volatilize the solvent and preliminarily react and cure the adhesive, to make a prepreg;

[0070] 1.6.3 Layout, pressing;

[0071] a. The prepreg is cut into the same size, 12 pieces per group, and then laminated with copper foil, and then pressed.

[0072] The specific pressing parameters are as follows:

[0073] a. Pressure: 70-600 psi;

[0074] b. Temperature: 70-240 °C;

[0075] c. Vacuum: 0.02-0.1 Mpa;

[0076] d. Curing time: 90 min;

[0077] e. Pressing time: 160 min.

[0078] The above glass cloth-based copper-clad foil plate can have various types of specifications and sizes, such as 36x48, 37x49, 40x48, 40.5x48.5, 41x49, 42.5x48.5, 43x49, etc. (unit: inch).

[0079] The glass fiber cloth can be selected from E-grade, and the specifications can be selected from 1035, 1078, 1080, 2113, 2116, 3313, etc.

[0080] The copper foil can be selected from 1 / 3 oz, Hoz, 1 oz, 2 oz, 3 oz, 4 oz, or RTF copper foil.

[0081] Table 1

[0082]

[0083] Note:

[0084] The preparation method of Examples 2-6 in Table 1 is the same as that of Example 1.

[0085] Table 2

[0086]

[0087] Glass transition temperature (Tg): The Tg of the laminate was determined according to the DMA method specified in IPC-TM-650 24.24.4, dynamic mechanical analysis (DMA) method;

[0088] Peeling strength: tested according to IPC-TM-650 2.4.8 method;

[0089] Dielectric constant (Dk) and dielectric loss factor (Df): determined according to SPDR method;

[0090] Flame retardant performance: tested according to UL94 method.

[0091] As can be seen from Table 1 and Table 2, in Examples 1-6, the combination of reactive phosphorus-containing flame retardant and additive flame retardant not only improves the dielectric properties, increases the adhesion between copper foil and resin, and improves the peel strength of the substrate, but also plays a synergistic effect in improving the flame retardancy from different mechanisms, so that the flame retardant properties of the substrate reach the V-0 level.

[0092] Comparing Example 1 with Examples 2 / 3, the reactive phosphorus-containing flame retardant is added, the groups on the flame retardant react with the groups on the polymer chain to become part of the polymer chain, and the flame-retardant groups are introduced into the polymer material through chemical reaction, thereby improving the flame resistance of the material, having good compatibility, improving the peel strength, and also improving the heat resistance.

[0093] Comparing Example 3 with Examples 4 / 5 / 6, although the content of PQ60 is increased, the flame retardant properties of the substrate are also improved, the increase in the content of PQ60 leads to poor compatibility of the matrix polymer resin, poor adhesion of the resin to the copper foil, reduced peel strength, and higher cost.

[0094] As described above, compared with general laminates, the combination of halogen-free additive flame retardant and reactive flame retardant in the present application provides the substrate with excellent flame retardant properties, high peel strength, and excellent dielectric properties, and can be better applied in high-speed circuit substrates.

Claims

1. A flame retardant composition for use in prepreg laminates, characterized in that, for: 5-60 parts of reactive phosphorus-nitrogen flame retardant; 3-45 parts of DOPO derivative flame retardant; 20-80 parts of thermosetting polyphenylene ether resin; The reactive phosphorus-nitrogen flame retardant is Otsuka SPV-100 reactive flame retardant from Japan. The DOPO derivative flame retardant is PQ60, a DOPO derivative flame retardant from Taiwan Jin Yi Chemical Co., Ltd. The thermosetting polyphenylene ether resin is a modified thermosetting polyphenylene ether resin. The modified thermosetting polyphenylene ether resin is a methacrylate-based modified thermosetting polyphenylene ether resin, and the number average molecular weight of the methacrylate-based modified thermosetting polyphenylene ether resin is 1000-3200 g / mol.

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