CN102250383B - Halogen-free fire retardant containing benzoxazine and polymer material comprising same - Google Patents

Abstract

The invention relates to a halogen-free flame retardant containing benzoxazine and a polymer material containing the halogen-free flame retardant. At the same time, a small amount of metal oxide or hydroxide can be added as a flame retardant synergist. Phosphorus oxide, phosphoric acid, metaphosphoric acid, polyphosphoric acid, etc. generated by red phosphorus combustion react with a large number of phenolic hydroxyl groups generated by benzoxazine resin to dehydrate to form an inorganic-organic hybrid barrier layer, which has good wettability to the matrix polymer , the barrier property is improved; at the same time, the organic part has the absorption effect on the organic fume, so that the flame retardant efficiency is greatly improved. A small amount of metal oxide or hydroxide can enhance the stability of the barrier layer and further improve the flame retardant effect. The composition is used for flame retardant of polymers, polymer-based compositions and products thereof, and has good flame retardant effect. The halogen-free flame retardant system of the invention has the characteristics of low cost, wide application range and good flame retardancy.

Description

Halogen-free flame retardant containing benzoxazine and polymer material containing halogen-free flame retardant

technical field

The invention relates to a flame-retardant non-halogen flame retardant for polymers and a polymer material containing the non-halogen flame retardant.

Background technique

Most of the polymer materials used in large quantities in our daily life are extremely flammable. For example, the limiting oxygen index of ABS is 18.3-20, and the limiting oxygen index of high-impact polystyrene (HIPS) is 18, which are extremely flammable materials, and polyolefin materials are also flammable in the air. In practical applications, it is necessary to add flame retardants to make them flame retardant.

At present, traditional halogenated flame retardants are mainly used in the domestic market, among which bromine-containing organic compounds have the best flame retardant effect. Although the flame retardant effect of halogenated flame retardants is good, more smoke, harmful gases and corrosive gases are produced during combustion, which will cause harm to the environment and human body. Therefore, the development of halogen-free flame retardant materials is a research and development hotspot in this field. A halogen-free barrier flame retardant composed of three elements of acid source, carbon source and gas source, which has a good flame retardant effect on specific polymers, and its representatives are ammonium polyphosphate, pentaerythritol and triacylamine. Due to the large amount of addition, poor water resistance and few suitable polymers, this system is difficult to be popularized and used in large quantities. Although the modified phosphate ester based on this has good compatibility with the matrix polymer and good flame retardancy, it has high cost and large addition amount. Among them, the halogen-free flame-retardant products prepared by blending PC and ABS with phosphate flame retardants have good commercial applications. A halogen-free and phosphorus-free flame-retardant PC/ABS alloy material with publication number CN101089045A and a halogen-free flame-retardant PC/ABS alloy with publication number CN101418118B and its preparation method are representatives in this respect.

Due to its high phosphorus content and good flame retardant effect, red phosphorus flame retardant is currently the main type of halogen-free flame retardant. Publication No. CN101200576A discloses a polybutylene terephthalate molding composition containing red phosphorus flame retardant, and CN101235174A discloses an environmentally friendly halogen-free flame-retardant polypropylene composite material. These two patents use red phosphorus flame retardants and inorganic flame retardants to compound flame retardant polymers, and the addition of large amounts of inorganic flame retardants is not conducive to processing.

The highly effective flame retardants currently used in electronic products are phosphinates. US Patent 7608654 reports that a halogen-free flame-retardant polycarbonate is mainly composed of phosphinate; US Patent 7,803,856 discloses a flame-retardant polyamide composed of phosphonate, nitrogen-containing compounds and untreated clay. Phosphinate has a wide range of highly effective flame retardant effects due to having both organic and inorganic parts in one molecule. However, its production cost is high.

This field lacks a halogen-free flame retardant system with low cost, easy processing, good flame retardancy and wide applicability.

Contents of the invention

The purpose of the present invention is to overcome the defects of the prior art and provide a halogen-free flame retardant with wide application range, low cost and high efficiency and a polymer material containing the halogen-free flame retardant.

The object of the invention is achieved through the following technical solutions:

Halogen-free flame retardant containing benzoxazine and red phosphorus, consisting of benzoxazine resin, red phosphorus and metal oxide or metal hydroxide;

Wherein the weight ratio of benzoxazine resin to red phosphorus is 0.25~4; preferably 0.5~2.

The metal oxide or metal hydroxide accounts for 0-10% by weight of the total weight of the benzoxazine resin and red phosphorus.

Described benzoxazine resin is monooxazine ring benzoxazine resin, and its structural formula is:

Wherein R ₁ is H, an alkane group or an aromatic hydrocarbon group; R ₂ is an alkane group or an aromatic hydrocarbon group.

Preferably R ₁ is H, or tert-butyl; R ₂ is phenyl or tert-butyl.

More preferably R ₁ is H; R ₂ is phenyl.

More preferably, the monooxazine ring benzoxazine resin is a phenolic benzoxazine, and its structural formula is as follows:

。

.

The benzoxazine resin can also be a bisoxazine ring benzoxazine resin, and its structural formula is:

The benzoxazine resin can also be a bisphenol type bisoxazine ring benzoxazine resin or a diamine type bisoxazine ring benzoxazine resin; the bisphenol type structural formula is as follows:

Wherein R ₁ is an alkane group or an aromatic group; R ₂ is an alkane group or an aromatic group;

The structural formula of diamine type is as follows:

Wherein R ₁ is an alkane group or an arene group; R ₂ is H, an alkane group or an arene group.

Preferred bisphenol type bisoxazine ring benzoxazine resin, structural formula is:

Wherein R ₁ is CH ₂ , C(CH ₃ ) ₂ or negative phenyl group (this time is hydroquinone type bisoxazine ring benzoxazine resin); R ₂ is phenyl group, tert-butylphenyl group or other An aromatic hydrocarbon group and a C ₄ -C ₁₈ straight chain or branched chain alkane group.

More preferably, the bisphenol type bisoxazine ring benzoxazine resin is a bisphenol A type benzoxazine resin, and its structural formula is as follows:

 。

.

The red phosphorus is pure red phosphorus or microencapsulated red phosphorus. The microencapsulated red phosphorus is achieved by coating the surface of the red phosphorus with a layer of triacrylonitrile-amine formaldehyde resin to realize the microencapsulation treatment of the red phosphorus.

The metal hydroxide is aluminum hydroxide or magnesium hydroxide; the metal oxide is magnesium oxide or zinc oxide.

A polymer material containing the halogen-free flame retardant, including the halogen-free flame retardant and a polymer; the polymer is selected from the group consisting of styrene polymers, benzene ring-containing polymers, polyolefin polymers Or their blends; wherein the amount of halogen-free flame retardant is 5~25%wt of the weight of the polymer.

The polymer material containing said halogen-free flame retardant may also include one or more of tougheners, compatibilizers, antioxidants, lubricants, stabilizers, antistatic agents, pigments, fillers or reinforcing materials. kind.

Styrene polymers are selected from acrylonitrile-butadiene-styrene copolymer (ABS), polystyrene (PS), high-impact polystyrene (HIPS), styrene-acrylonitrile copolymer, acrylonitrile- Styrene-EPDM copolymer (AES), acrylonitrile-styrene-acrylic acid copolymer (ASA), methyl methacrylate-butadiene-styrene copolymer (MBS), methyl methacrylate - Acrylate-styrene copolymer (MAS), styrene-butadiene-styrene block copolymer (SBS) or styrene-isoprene-styrene block copolymer (SIS).

The benzene ring-containing polymer is selected from ethylene terephthalate (PET), butylene terephthalate (PBT) or polycarbonate (PC).

The best several applications of the flame retardant of the present invention:

ABS, HIPS, PC/ABS polymer materials and products compounded with BPOZ or BOZ and red phosphorus for flame retardancy.

Flame-retardant SBS and SIS elastomer materials and products made of BPOZ or BOZ and red phosphorus.

PET, PBT, nylon and other polymer materials and products made of BPOZ or BOZ and red phosphorus composite flame-retardant.

PP, PE and other polyolefin materials and products are flame-retardant with benzoxazine resin containing C ₄ ~C ₁₈ long carbon chain structure.

The benzoxazine resin can be synthesized from a single phenol or amine, or their mutual reaction resin or resin mixture, so as to match the compatibility with the matrix resin.

Bisphenol A benzoxazine (BPOZ) can be prepared according to the preparation method in ZL 200710032522.X. It is synthesized from bisphenol A, aniline and paraformaldehyde in a molar ratio of 1:2:4.

Phenol-type benzoxazine (BOZ) can be synthesized from phenol, aniline, and paraformaldehyde at a molar ratio of 1:1:2

The benzoxazine resin (taking phenol-type oxazine resin as an example) is partially cured during processing and forms phenolic hydroxyl groups when it is burned in a fire. The reaction formula is as follows:

Phosphorus oxide, phosphoric acid, metaphosphoric acid, polyphosphoric acid, etc. generated when the red phosphorus is burned react with some phenolic hydroxyl groups to form inorganic-organic hybrids:

Inorganic-organic hybrids are formed by the reaction of benzoxazine and red phosphorus in the process of heating and burning. Because of its good compatibility with the organic matrix, it can completely wet and cover the surface of the matrix, and has a good barrier effect. In addition, it can also absorb and capture the smoke and dust formed by combustion, making it a part of the barrier layer, which doubles the flame retardant efficiency.

The application of the halogen-free flame retardant in the flame retardancy of styrene polymers, benzene ring-containing polymers or polyolefin polymers and their blends.

Compared with the prior art, the present invention has advantages and beneficial effects.

(1) The halogen-free flame retardant system based on benzoxazine and red phosphorus proposed by the technical solution of the present invention fully exerts the synergistic effect between benzoxazine and red phosphorus, and has better flame retardancy than adding red phosphorus alone. A substantial increase.

(2) At the same time, for the flame-retardant matrix, a specific benzoxazine resin with good compatibility with the matrix can be selected, which has the characteristics of wide applicability and good flame retardancy.

(3) Inorganic-organic hybrids are formed by the reaction of benzoxazine and red phosphorus in the process of heating and burning. Because of its good compatibility with the organic matrix, it can completely wet and cover the surface of the matrix, and has a good barrier effect. In addition, it can also absorb and capture the smoke and dust formed by combustion, making it a part of the barrier layer, which doubles the flame retardant efficiency.

Detailed ways

The following examples are detailed descriptions of the present invention, but the present invention is not limited to these examples.

Embodiment 1-8:

The preparation process of Comparative Examples 1-2 and Examples 1-8: After a certain amount of ABS or HIPS is plasticized on a double-roll mill at 170-180°C, antioxidants (mass Antioxidants 1076 and 168 with a ratio of 1:1), benzoxazine resin, microcapsule red phosphorus and other raw materials, after mixing evenly, put them in the mold after discharging, and heat press on a flat vulcanizing machine at 180°C for 10 Minutes, then cold press at room temperature for 10 minutes, and then molded boards for performance testing. The test standard is shown in Table 6.

The physical properties of the benzoxazine-based halogen-free flame-retardant ABS in the comparative examples and examples are shown in Table 2, and the test standards are shown in Table 6. In Example 1, 9 parts of bisphenol A-type benzoxazine was used to replace 9 parts of microencapsulated red phosphorus, and the tensile strength, impact strength and flame retardancy of the material prepared were all improved. In Examples 2 and 3, the amount of benzoxazine and microencapsulated red phosphorus is further increased, and the flame retardancy of the material is further improved. At the same time, after adding nitrile rubber, the impact strength of the obtained material is improved.

Table 1 Flame-retardant ABS and HIPS blending formula/(weight parts)

the Comparative example 1 Comparative example 2 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 ABS 100 85 84.7 78 69 76 76 76 — HIPS — — — — — — — — 74 Bisphenol A benzoxazine — — 9 11 15 10 8 — 12 Phenol benzoxazine — — — — — — — 10 — Microencapsulated red phosphorus — 15 6 7 10 10 12 10 8 Aluminum hydroxide — — 0.6 — — — — — — Nitrile rubber — — — 4 6 4 4 4 6 antioxidant 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2

Table 2 Physical properties of flame retardant ABS and HIPS

 

Embodiment 9~10

After mixing all the components in proportion (see Table 3), put them into a twin-screw extruder for melt extrusion, and the extrusion temperature is 200~250°C. The extruded material is granulated and post-processed, and then injection molded to obtain test specimens. Antioxidants are selected from antioxidant 1076 and 168 composite antioxidants with a mass ratio of 1:1. Table 3 Flame-retardant PC/ABS alloy formula/(weight parts)

 

The physical properties of the benzoxazine-based halogen-free flame-retardant PC/ABS alloys in the comparative examples and examples are shown in Table 4, and the test standards are shown in Table 6.

Table 4 Physical Properties of Flame Retardant PC/ABS Alloy

project Comparative example Example 9 Example 10 Tensile strength (MPa) 52 46 42 Notched impact strength (KJ m ^-2 ) 42 38 32 Flame retardant (1.6mm) combustion V-1 V-0

Example 11

Mix 10 parts of BPOZ with 10 parts of red phosphorus powder and 0.2 parts of magnesium hydroxide evenly, and then add them to a twin-screw extruder with a temperature set at 120°C to extrude and granulate to obtain a non-toxic compound containing benzoxazine and red phosphorus. Halogen flame retardant A.

Mix 10 parts of ABS with 1.8 parts of the above-mentioned halogen-free flame retardant A containing benzoxazine and red phosphorus, extrude and granulate on a twin-screw extruder at 200°C, and then put the obtained flame-retardant ABS on an injection molding machine at Sample preparation by injection molding at 220°C. The properties of the obtained samples are shown in Table 5

Table 5 Example 11 sample properties

project Example 11 Tensile strength (MPa) 35 Notched impact strength (KJ m ^-2 ) 6.3 Flame retardant (1.6mm) V-0

Example 12

  30 parts of BPOZ, 30 parts of granular red phosphorus and 0.6 parts of aluminum hydroxide were mixed and placed in a high-speed pulverizer, ground and pulverized under nitrogen protection to obtain a halogen-free flame retardant B containing benzoxazine and red phosphorus.

Add 10 parts of halogen-free flame retardant B containing benzoxazine and red phosphorus to 80 parts of an adhesive formulated with SBS/terpene resin with a solid content of 50%, stir it evenly, and spread it on the acetate cloth. The coating thickness is about 200 microns, and the halogen-free flame-retardant pressure-sensitive adhesive tape is prepared. The flame retardant performance of this tape reaches UL 94 V-0 level.

Example 13

Mix 7.9 parts of ABS plastic, 1.0 part of phenolic benzoxazine resin, 1.0 part of microcapsule red phosphorus, 0.6 part of nitrile rubber powder, 0.2 part of antioxidant, and 0.1 part of black masterbatch in a high-speed mixer, Then add the mixture into a twin-screw extruder whose temperature is controlled at 210-230° C. to extrude and pelletize to obtain black flame-retardant ABS pellets C.

Dry the ABS pellet C at 80°C, put it into an injection molding machine at a temperature of 230°C, and inject it into the mold of the electrical remote control switch box to obtain a halogen-free flame-retardant electrical remote control switch box D.

The switch box is hung in a vertical and horizontal combustion tester, and the ignition and combustion test shows that the product is self-extinguishing when it leaves the fire, reaching the level of UL 94 V-0.

Table 6 Test Standards

project standard test Tensile Strength GB/T1040-2006 Notched impact strength GB/T1843-1996 flame retardant UL-94

Claims (8)

1. The halogen-free flame retardant containing benzoxazine is characterized in that, it is composed of monooxazine ring benzoxazine resin, bisphenol type bisoxazine ring benzoxazine resin or diamine type bisoxazine ring benzene Composition of oxazine resin, red phosphorus and metal oxide or metal hydroxide; Wherein the weight ratio of monooxazine ring benzoxazine resin, bisphenol type bisoxazine ring benzoxazine resin or diamine type bisoxazine ring benzoxazine resin to red phosphorus is 0.25-4; Metal oxide or metal hydroxide accounts for the total weight of monooxazine ring benzoxazine resin, bisphenol type bisoxazine ring benzoxazine resin or diamine type bisoxazine ring benzoxazine resin and red phosphorus 0~10% by weight; Wherein, the structural formula of the monooxazine ring benzoxazine resin is: Wherein R ₁ is H, an alkane group or an aromatic hydrocarbon group; R ₂ is an alkane group or an aromatic hydrocarbon group; The structural formula of the bisphenol type bisoxazine ring benzoxazine resin is as follows:

Wherein R ₁ is an alkane group or an aromatic group; R ₂ is an alkane group or an aromatic group; The structural formula of the diamine type bisoxazine ring benzoxazine resin is as follows:

Wherein R ₁ is an alkane group or an arene group; R ₂ is H, an alkane group or an arene group. 2. The halogen-free flame retardant according to claim 1, wherein the monooxazine ring benzoxazine resin is a phenol-type benzoxazine, and its structural formula is as follows:

3. The halogen-free flame retardant according to claim 1, wherein the bisphenol type bisoxazine ring benzoxazine resin is a bisphenol A type benzoxazine resin, and its structural formula is as follows: 4. The halogen-free flame retardant according to any one of claims 1-3, characterized in that the red phosphorus is pure red phosphorus or microencapsulated red phosphorus. 5. The halogen-free flame retardant according to claim 4, wherein the metal hydroxide is aluminum hydroxide or magnesium hydroxide; the metal oxide is magnesium oxide or zinc oxide. 6. Polymer materials and products containing the halogen-free flame retardant according to claim 1, characterized in that, comprising the halogen-free flame retardant and the polymer according to claim 1; the polymer is selected from the group consisting of benzene ring-containing Polymers, polyolefin polymers or their blends; wherein the amount of the halogen-free flame retardant is 5-25%wt of the weight of the polymer. 7. The polymer material and product of halogen-free flame retardant according to claim 6, characterized in that, it also includes toughening agent, compatibilizer, antioxidant, lubricant, stabilizer, antistatic agent, pigment , one or more of fillers or reinforcing materials. 8. The application of the halogen-free flame retardant according to claim 1 in the flame retardancy of benzene ring-containing polymers or polyolefin polymers and their blends.