阅读说明：本技术 一种含磷的反应型阻燃剂及其制备方法和应用 (Phosphorus-containing reactive flame retardant and preparation method and application thereof ) 是由 潘庆崇 于 2019-08-28 设计创作，主要内容包括：本发明提供了一种含磷的反应型阻燃剂及其制备方法和应用,所述含磷的反应型阻燃剂由带有-P-H反应基团的化合物与含有羰基的化合物通过加成反应得到；本发明所提供的含磷的反应型阻燃剂,结构中具有活性基团羟基,当这样的结构制备复合材料时,能够使得含磷的反应型阻燃剂高效的参与到反应中,并且性质稳定,物理性能突出,高效阻燃,避免了现有的阻燃剂的析出现象,克服了添加型阻燃剂存在的问题,具有较高的应用价值。(The invention provides a phosphorus-containing reactive flame retardant, a preparation method and application thereof, wherein the phosphorus-containing reactive flame retardant is obtained by an addition reaction of a compound with a-P-H reactive group and a compound containing a carbonyl group; the structure of the phosphorus-containing reactive flame retardant provided by the invention has active group hydroxyl, when the composite material is prepared by the structure, the phosphorus-containing reactive flame retardant can efficiently participate in the reaction, and the phosphorus-containing reactive flame retardant has stable property, outstanding physical property and high-efficiency flame retardance, avoids the precipitation phenomenon of the existing flame retardant, overcomes the problems of an additive flame retardant and has high application value.)

1. The phosphorus-containing reactive flame retardant is characterized in that the phosphorus-containing reactive flame retardant is obtained by an addition reaction of a compound with a-P-H reactive group and a compound containing a carbonyl group.

2. The reactive phosphorus-containing flame retardant of claim 1, wherein the compound having a reactive group-P-H has a structure according to formula I:

wherein X is a VI main group element or is absent, L₁、L₂Each independently is preferably alkyl, cycloalkyl, aryl, heteroaryl, alkoxy, alkanoyl or aryloxy, or L₁And L₂Are connected into a ring.

3. The reactive phosphorus-containing flame retardant according to claim 2, wherein X is preferably an oxygen atom or a sulfur atom, and further preferably an oxygen atom;

preferably, said L₁、L₂Are each independently preferably C₁-C₅Alkoxy group of (C)₆-C₉Aryl or C of₆-C₉Aryloxy group of, or L₁And L₂Are connected into a ring.

4. The reactive flame retardant containing phosphorus according to any one of claims 1 to 3, wherein the number of carbonyl groups in the compound containing a carbonyl group is 1 to 5; preferably 1 to 2.

5. The reactive phosphorus-containing flame retardant according to any one of claims 1 to 4, wherein the carbonyl group-containing compound is preferably

Wherein R is₁、R₂Independently selected from any one of hydrogen, alkyl, substituted alkyl, aryl or substituted aryl;

n is an integer of 0 to 10, preferably 1 to 4;

and when n is 0, R₁、R₂Not hydrogen at the same time.

6. The reactive flame retardant containing phosphorus according to any one of claims 1 to 5, wherein the reactive flame retardant containing phosphorus has a structure preferably selected from the group consisting of Any one of them.

7. The reactive flame retardant containing phosphorus according to any one of claims 1 to 6, wherein the reactive flame retardant containing phosphorus has a structure that is preferably

8. The method of any of claims 1-7, wherein the method comprises: and carrying out addition reaction on a compound with a-P-H reaction group and a compound containing carbonyl under the catalysis of acid or alkali to obtain the phosphorus-containing reactive flame retardant.

9. An epoxy resin curing agent comprising the phosphorus-containing reactive flame retardant according to any one of claims 1 to 7.

10. A polyurethane comprising the phosphorus-containing reactive flame retardant according to any one of claims 1 to 7.

Technical Field

The invention belongs to the technical field of flame retardants, and relates to a phosphorus-containing reactive flame retardant, and a preparation method and application thereof.

Background

The reactive flame retardant is added into a reaction system in the process of high-molecular polymerization reaction, participates in the reaction in a monomer form, and becomes a part of a polymer through chemical bonding. The phosphorus flame retardant has the characteristics of high efficiency, no smoke, low toxicity, no pollution and the like, has the advantages of small influence on the physical and mechanical properties of products and lasting flame retardant property compared with an additive flame retardant, and is widely applied to thermosetting resins such as polyurethane, epoxy resin, unsaturated polyester, phenolic resin and the like. But the reactive flame retardant has less varieties, difficult monomer preparation and high cost.

CN109336927A discloses a preparation method of a phosphine reaction type flame retardant monomer, which comprises the following steps: preparing a compound with a structure shown in a formula VI or a formula VII;

hydrolyzing the compound with the structure of the formula VI or VII under the action of an alkali solution, adding an acid solution to adjust acid, adding an inorganic salt to perform saturation treatment, adding an organic solvent to extract, and evaporating the organic solvent to dryness to obtain the compound with the structure of the formula VIII or IX;

adding a dehydrating agent into a compound with a structure of formula VIII or IX to dehydrate and cyclize the compound with the structure of formula VIII or IX to obtain a phosphine reaction type flame retardant monomer with the structure of formula I or II;

in the formula I, the formula II, the formula VI, the formula VII, the formula VIII and the formula IX, R₁、R₂Is methyl or ethyl. The preparation method of the phosphine reaction type flame retardant monomer prepared by the method has the advantages of simple process, high reaction yield, simple and convenient operation, no need of special equipment, sufficient and reliable raw material source, low cost, environmental protection and suitability for industrial production. However, the steps are many and complicated.

CN105061711A discloses a DOPO type reactive flame retardant with an end group as an epoxy group, a preparation method and an application thereof, wherein the DOPO and a polyglycidyl compound are subjected to a reaction molar ratio in an organic solvent, a heating reaction is carried out, the solvent is removed under reduced pressure, and the reactive flame retardant which is viscous liquid at room temperature, contains a DOPO flame retardant group and has the end group as the epoxy group is obtained. The synthetic method of the flame retardant is simple, easy to control, good in repeatability and high in yield, is suitable for large-scale production, and can be used as an end-capped flame retardant to be applied to flame retardance of polyurethane materials. When the flame retardant is applied to a polyurethane material, the defects that an additive flame retardant is poor in compatibility with a matrix, easy to lose in the using process and the like are overcome, the complex process of synthesizing polyol by applying a reaction type flame retardant in the prior art is avoided, and the flame retardant property of the material is obviously improved. However, the performance of such reactive flame retardants still needs to be further improved.

Therefore, how to develop a novel phosphorus-containing reactive flame retardant has important significance and value for the future application of the flame retardant.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a phosphorus-containing reactive flame retardant, a preparation method and application thereof, so as to solve the problems of unstable phosphorus-containing flame retardant performance and low physical performance in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a reactive flame retardant comprising phosphorus, which is obtained by an addition reaction of a compound having a-P-H reactive group and a carbonyl group-containing compound.

The phosphorus-containing reactive flame retardant provided by the invention has active group hydroxyl in the structure, can efficiently participate in the reaction when the composite material is prepared by the structure, has stable property and outstanding physical property, is efficient in flame retardance, avoids the precipitation phenomenon of the existing flame retardant, overcomes the problems of the additive flame retardant, and has high application value.

The carbonyl group-containing compound of the present invention may contain not only one reactive group of a carbonyl group but also other reactive groups such as an alkenyl group, an alkynyl group, a hydroxyl group, etc. in addition to the carbonyl group.

Preferably, the compound having a-P-H reactive group has the structure shown in formula I:

wherein X is a VI main group element or is absent, L₁、L₂Each independently is preferably alkyl, cycloalkyl, aryl, heteroaryl, alkoxy, alkanoyl or aryloxy, or L₁And L₂Are connected into a ring.

Preferably, X is an oxygen atom or a sulfur atom, further preferably an oxygen atom;

preferably, said L₁、L₂Are each independently preferably C₁-C₅Alkoxy group of (C)₆-C₉Aryl or C of₆-C₉Aryloxy group of, or L₁And L₂Are connected into a ring.

Wherein, C₁-C₅May be C₁、C₂、C₃、C₄Or C₅Etc. C₆-C₉May be C₆、C₇、C₈Or C₉And the like.

Illustratively, the compound having a-P-H reactive group may be 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), dimethyl phosphite, diethyl phosphite or diphenyl phosphite, and the like.

Preferably, the number of carbonyl groups in the carbonyl group-containing compound is 1 to 5, and for example, the number may be 1,2, 3, 4, or 5, and preferably 1 to 2.

Preferably, the carbonyl-containing compound isI.e. preferably a compound having a monoketone, diketone, monoaldehyde or dialdehyde structure. Such a structure facilitates the progress of the addition reaction and the cost of the raw material is lower.

Wherein R is₁、R₂Independently selected from hydrogen,Any one of an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group.

The alkyl in the invention can be a straight-chain alkyl, can also be an alkyl with a branched chain, and can have a cyclic structure, a spiro structure and the like. The aryl of the invention can be aromatic compounds with benzene, naphthalene, anthracene, phenanthrene and other structures, and the heteroaryl refers to compounds with aromaticity containing atoms of sulfur, nitrogen and oxygen.

The substitution in the present invention refers to the substitution of alkyl or aryl groups by any substituent, such as hydroxyl, amino, carboxyl, etc., which are well known to those skilled in the art.

n is an integer of 0 to 10, and may be, for example, 0, 1,2, 3, 4, 5, 6, 7, 8, 9 or 10, etc., preferably 1 to 4, and may be, for example, 1,2, 3 or 4.

And when n is 0, R₁、R₂Not hydrogen at the same time.

Preferably, the structure of the phosphorus-containing reactive flame retardant is preferably

Any one of them.

Preferably, the structure of the phosphorus-containing reactive flame retardant is preferably

In a second aspect, the present invention provides a method for preparing the phosphorus-containing reactive flame retardant according to the first aspect, the method comprising: and carrying out addition reaction on a compound with a-P-H reaction group and a compound containing carbonyl under the catalysis of acid or alkali to obtain the phosphorus-containing reactive flame retardant.

The acid or base catalysis in the invention can be performed by selecting a commonly used acid or a commonly used base according to the actual addition reaction condition by a person skilled in the art, so that the addition reaction is performed in a forward direction.

In a third aspect, the present invention provides an epoxy resin curing agent comprising the phosphorus-containing reactive flame retardant of the first aspect.

In a fourth aspect, the present invention provides a polyurethane comprising the phosphorus-containing reactive flame retardant of the first aspect.

Compared with the prior art, the invention has the following beneficial effects:

the phosphorus-containing reactive flame retardant provided by the invention has active group hydroxyl in the structure, can efficiently participate in the reaction when the composite material is prepared by the structure, has stable property and outstanding physical property, is efficient in flame retardance, avoids the precipitation phenomenon of the existing flame retardant, overcomes the problems of the additive flame retardant, and has high application value and application prospect.

The phosphorus-containing reactive flame retardant provided by the invention is simple in synthesis method, can be prepared by only one-step reaction, and is suitable for industrial production.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

The implementation provides a phosphorus-containing reactive flame retardant, which has the following structure:

the preparation method comprises the following steps: dissolving 0.3mol of dimethyl phosphite and 0.14mol of 2, 4-pentanedione in 500mL of 1, 2-dichloroethane, controlling the temperature in an ice-water bath to be below 5 ℃ under stirring, stirring and refluxing in the presence of triethylamine for 1h, and after the reaction is finished, carrying out reduced pressure distillation to obtain the reactive flame retardant with the structure.

¹H NMR(400MHz,DMSO-d₆)δ6.61(s,2H),3.43(d,J＝10.8Hz,12H),1.75(s,2H),1.31(s,6H).

Example 2

The implementation provides a phosphorus-containing reactive flame retardant, which has the following structure:

the preparation method comprises the following steps: dissolving 0.2mol of diethyl phosphite and 0.09mol of butanedione in 300mL of chloroform, stirring and refluxing in the presence of potassium carbonate for reaction for 8 hours, washing with dilute hydrochloric acid and water after the reaction is finished, and extracting with dichloromethane to obtain the phosphorus-containing reactive flame retardant.

¹H NMR(400MHz,DMSO-d₆)δ6.44(s,2H),4.30(dp,J＝12.3,8.0Hz,4H),3.80(dp,J＝12.3,8.0Hz,4H),1.50–1.26(m,18H).

Example 3

The implementation provides a phosphorus-containing reactive flame retardant, which has the following structure:

the preparation method comprises the following steps: 0.2mol of diphenyl phosphite and 0.09mol of butanedione are dissolved in 500mL of toluene, the mixture is stirred and refluxed for reaction for 6 hours in the presence of cesium carbonate, and after the reaction is finished, diluted hydrochloric acid is directly used for pickling, and water is directly used for washing a spin-dried solvent to obtain the phosphorus-containing reactive flame retardant.

¹H NMR(400MHz,DMSO-d₆)δ7.82–7.08(m,20H),5.67(s,1H),5.54(s,1H),1.50(d,J＝13.5Hz,6H).

Example 4

The implementation provides a phosphorus-containing reactive flame retardant, which has the following structure:

the preparation method comprises the following steps: dissolving 0.2mol of DOPO and 0.09mol of glyoxal in 500mL of toluene, stirring and refluxing for 8 hours in the presence of cesium carbonate, washing with water after the reaction is finished, and evaporating the solvent to obtain the phosphorus-containing reactive flame retardant.

¹H NMR(400MHz,DMSO-d₆)δ8.03–7.30(m,16H),6.21(dd,J＝4.1,1.0Hz,2H),3.91–3.78(m,2H).

Example 5

The implementation provides a phosphorus-containing reactive flame retardant, which has the following structure:

the preparation method comprises the following steps: dissolving 0.2mol of DOPO and 0.09mol of butanedione in 500mL of toluene, stirring and refluxing in the presence of cesium carbonate for reaction for 3 hours, washing with dilute hydrochloric acid and water after the reaction is finished, and evaporating the solvent to obtain the phosphorus-containing reactive flame retardant.

¹H NMR(400MHz,DMSO-d₆)δ8.17–7.18(m,16H),5.39(s,2H),1.50(s,6H).

Example 6

The implementation provides a phosphorus-containing reactive flame retardant, which has the following structure:

the preparation method comprises the following steps: dissolving 0.3mol of dimethyl phosphite and 0.14mol of 2, 5-hexanedione in 500mL of 1, 2-dichloroethane, stirring and refluxing for reaction for 4h in the presence of potassium carbonate, washing with water after the reaction is finished, and distilling to obtain the phosphorus-containing reactive flame retardant.

¹H NMR(400MHz,DMSO-d₆)δ3.43(d,J＝10.8Hz,12H),1.36-1.40(m,4H),1.21(s,6H).

Example 7

The implementation provides a phosphorus-containing reactive flame retardant, which has the following structure:

the preparation method comprises the following steps: dissolving 0.3mol of dimethyl phosphite and 0.14mol of hexanedial in 500mL of 1, 2-dichloroethane, stirring and refluxing in the presence of potassium carbonate for 8 hours, directly washing with water after the reaction is finished, and spin-drying the solvent to obtain the phosphorus-containing reactive flame retardant.

¹H NMR(400MHz,DMSO-d₆)δ5.51(d,J＝5.0Hz,2H),3.91(d,J＝10.9Hz,12H),3.55(m,2H),2.34–2.17(m,2H),1.88–1.61(m,4H),1.49–1.26(m,2H).

Example 8

The implementation provides a phosphorus-containing reactive flame retardant, which has the following structure:

the preparation method comprises the following steps: 0.3mol of diphenyl phosphite and 0.14mol of 2, 4-pentanedione are dissolved in 500mL of toluene, the mixture is stirred and refluxed for reaction for 8 hours in the presence of cesium carbonate, the solvent is removed after the reaction is finished, the mixture is directly washed by dilute hydrochloric acid and water after the reaction is finished, and the solvent is dried by spinning to obtain the phosphorus-containing reactive flame retardant.

¹H NMR(400MHz,DMSO-d₆)δ9.09(s,1H),7.53–7.03(m,20H),4.75(s,1H),1.95(s,2H),1.52(s,3H),1.34(s,3H).

Example 9

The implementation provides a phosphorus-containing reactive flame retardant, which has the following structure:

the preparation method comprises the following steps: dissolving 0.3mol of DOPO and 0.32mol of methyl ethyl ketone in 500mL of toluene, stirring and refluxing for reaction for 8h in the presence of potassium carbonate, removing dilute hydrochloric acid after the reaction is finished, washing with water, and spin-drying the solvent to obtain the phosphorus-containing reactive flame retardant.

¹H NMR(400MHz,DMSO-d₆)δ8.08–7.25(m,8H),4.96(s,1H),2.13–1.79(m,2H),1.55(s,3H),0.79(t,J＝8.0Hz,3H).

Example 10

The implementation provides a phosphorus-containing reactive flame retardant, which has the following structure:

the preparation method comprises the following steps: dissolving 0.3mol of DOPO and 0.31mol of acetaldehyde in 500mL of chloroform, stirring and refluxing for reaction for 8h in the presence of potassium carbonate, carrying out dilute hydrochloric acid washing and water washing after the reaction is finished, extracting with dichloromethane, and spin-drying the solvent to obtain the phosphorus-containing reactive flame retardant.

¹H NMR(400MHz,DMSO-d₆)δ8.03–7.28(m,8H),5.51(d,J＝4.9Hz,1H),3.68(m,1H),1.40(d,J＝6.8Hz,3H).

The application comprises the following steps:

the phosphorus-containing reactive flame retardants prepared in examples 1 to 10 were applied to polyurethanes, and the obtained polyurethanes were samples 1 to 10, respectively. The polyurethane comprises the following components in parts by weight:

40 parts by weight of phosphorus-containing reactive flame retardant, 100 parts by weight of isophorone diisocyanate, 55 parts by weight of hydroxyl-terminated polytetrahydrofuran having a molecular weight of 2000, 5 parts by weight of ethylene glycol and 1 part by weight of catalyst were mixed and extruded by a twin-screw extruder to obtain polyurethane particles. Wherein the phosphorus-containing reactive flame retardants correspond to the compounds provided in examples 1-10, respectively.

Comparative example 1

The phosphorus-containing flame retardant in the polyurethane is completely replaced by hydroxyl-terminated polytetrahydrofuran with molecular weight of 2000.

Comparative examples 2 to 3

On the basis of comparative example 1, triphenyl phosphate, which is a flame retardant, was added in an amount of 40 parts by weight (comparative example 2) and 75 parts by weight (comparative example 3).

And (3) performance testing:

the polyurethane particles provided in samples 1-10 and comparative examples 1-3 were tested for performance by the following method:

(1) combustibility: testing according to UL-94 vertical burning test standard;

(2) tensile strength and elongation: the method is carried out according to the regulation of GB/T528-2009, the test speed (500 +/-50) mm/min and the thickness of a sample are 10 mm;

(3) flame retardant stability: after soaking the polyurethane particles in water for 1h, they were dried and their combustibility was measured again.

The test results obtained are shown in table 1 below:

TABLE 1

Sample (I)	Combustibility	Tensile strength/MPa	Elongation at break/%	Combustibility after immersion in water
					1	V-0	51.2	204	V-0
2	V-0	50.8	199	V-0
					3	V-0	46.1	189	V-0
4	V-0	46.5	191	V-0
					5	V-0	46.8	193	V-0
6	V-0	53.5	208	V-0
					7	V-0	54.1	210	V-0
8	V-0	47.2	193	V-0
					9	V-0	42.5	181	V-0
10	V-0	42.1	179	V-0
					Comparative example 1	V-2	32.1	264	V-2
Comparative example 2	V-1	35.7	174	V-2
					Comparative example 3	V-0	36.4	124	V-1

As can be seen from the test results of the samples 1-10 and the comparative examples 1-3, when the phosphorus-containing reactive flame retardant provided by the invention is applied to polyurethane, the performance is more stable, and the flame retardant performance is more excellent, wherein the tensile strength is more than 42MPa, and the elongation at break is more than 179%.

It is clear from the comparison between samples 1 to 10 that the products obtained by the addition of the dicarbonyl structure are superior in properties to those obtained by the addition of the monocarbonyl.

Further, from the results of samples 1, 6 and 7, it is found that the farther the distance between the two carbonyl groups, i.e., the farther the hydroxyl groups are apart after addition, the better the performance of the dicarbonyl-structured compound, wherein the tensile strength is 51.2MPa or more and the elongation at break is 204% or more, which is due to the effect of hydrogen bonds in the molecule, affects the stability of the compound and thus the performance of the polyurethane.

The phosphorus-containing reactive flame retardant provided in examples 1 to 4 and 7 is applied to an epoxy resin composition as a flame retardant curing agent, and corresponds to the epoxy resin compositions 1 to 5, respectively, and the epoxy resin composition comprises the following specific components:

100 parts by weight of bisphenol A type epoxy resin (epoxy equivalent of 450g/eq), 30 parts by weight of flame-retardant curing agent, if the curing agent is insufficient, the curing agent is complemented by dicyandiamide, and 0.5 part by weight of 2-methylimidazole.

Comparative example 4

The difference from the above epoxy resin composition is that 30 parts by weight of the phosphorus-containing reactive flame retardant provided in example 1 was replaced with a dicyandiamide curing agent used in an amount sufficient for curing the epoxy resin.

Comparative examples 5 to 6

30 parts by weight (comparative example 5) and 45 parts by weight (comparative example 6) of triphenyl phosphate as a flame retardant were added to the case of comparative example 4.

Performance testing

The epoxy resin compositions 1 to 5 and the epoxy resin compositions provided in comparative examples 4 to 6 were prepared into copper clad laminates according to a known conventional method, and the following tests were performed:

(1)T_g: differential Scanning Calorimetry (DSC) according to the DSC method defined in IPC-TM-650 at 2.4.25;

(2) interlayer peel strength PS: testing the peel strength of the plate according to the experimental conditions of 'after thermal stress' in the IPC-TM-6502.4.8 method;

(3) dielectric constant (Dk) and dielectric loss factor (Df): testing the dielectric constant Dk and the dielectric loss Df of the board by adopting an SPDR method under the frequency of 10 GHz;

(5) combustibility: testing according to UL-94 vertical burning test standard;

(6) flame retardant stability: soaking the copper-clad plate in water for 1h, drying and measuring the combustibility of the copper-clad plate again;

(7) mobility: and baking the copper-clad plate at 150 ℃ for 2h, and testing the weight difference percentage before and after baking.

The results of the tests on the examples and comparative examples are shown in Table 2:

TABLE 2

As can be seen from the data obtained in Table 2, the copper-clad plate prepared by the phosphorus-containing reactive flame retardant provided by the invention has excellent and stable performance, wherein the glass transition temperature is 170-256 ℃, the peel strength is more than 0.81N/mm, the dielectric constant is less than 3.62(10GHz), and the dielectric loss is less than 0.0085(10 GHz). The results of comparative examples 4-6 show that the additive flame retardant can affect the performance such as the glass transition temperature of the copper-clad plate, and the flame retardant stability is poor.

The applicant states that the present invention is illustrated by the above examples to the phosphorus-containing reactive flame retardant of the present invention and the preparation method and application thereof, but the present invention is not limited to the above detailed method, i.e. it does not mean that the present invention must be implemented by relying on the above detailed method. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.