HIGHLY FLAME-RETARDANT ADHESIVE FOR HIGH POLYMER MATERIALS

Abstract

This invention relates to a highly flame-retardant adhesive for high-polymer materials. The adhesive contains a phenolic hydroxyl flame retardant which is prepared from organic amino compounds by one-step reaction with simple and controllable synthesis conditions and high synthesis efficiency; and then the highly flame-retardant adhesive can be obtained by blending the flame-retardant and the adhesive. The highly flame-retardant adhesive synthesized in the invention can be directly used as an adhesive for polymer materials to produce high adhesion strength, or used as a basic formula and prepared into composite adhesives through the addition of other fillers, or used as a primer agent to modify surfaces of polymer materials, so as to meet different needs on various special occasions.

Claims

1. A highly flame-retardant adhesive for high-polymer materials, characterized in that it is composed of base adhesive, filler and flame retardant in parts by mass as follows: 100 parts of base adhesive, 0-50 parts of filler, and 1-10 parts of flame retardant; the said flame-retardant is with a structure as shown in chemical formula (1): ##STR00003## in chemical formula (1), R.sub.2 to R.sub.5 are organic groups of either hydrogen atoms or non-hydrogen atoms; R.sub.1, R.sub.6 and R.sub.7 are organic groups of non-hydrogen atoms.

2. The highly flame-retardant adhesive for high-polymer materials according to claim 1, characterized in that the said flame-retardant is with a structure as follows: ##STR00004##

3. The highly flame-retardant adhesive for high-polymer materials according to claim 1, characterized in that the said base adhesive is epoxy adhesive, phenol aldehyde resin adhesive, isocyanate adhesive, or benzoxazine adhesive.

4. The highly flame-retardant adhesive for high-polymer materials according to claim 1, characterized in that the said filler is fumed silica, precipitated silica, carbon black, calcium carbonate, aluminum hydroxide or magnesium hydrate, or any of the above compounds treated with silazane.

5. The highly flame-retardant adhesive for high-polymer materials according to claim 4, characterized in that the said filler is silazane-treated white carbon black.

6. The highly flame-retardant adhesive for high-polymer materials according to claim 1, characterized in that the said highly flame-retardant adhesive also includes 1-10 parts of auxiliaries by mass.

7. The highly flame-retardant adhesive for high-polymer materials according to claim 6, characterized in that the said auxiliaries are heat-oxygen stabilizers, conductive agents, foaming agents, deep curing agents, pigments or plasticizers, etc.

8. The highly flame-retardant adhesive for high-polymer materials according to claim 1, characterized in that the said highly flame-retardant adhesive also includes 1-10 parts of catalyst by mass.

9. The highly flame-retardant adhesive for high-polymer materials according to claim 1, characterized in that the said catalyst is acetic acid.

10. The highly flame-retardant adhesive for high-polymer materials according to claim 1, characterized in that the said flame-retardant is prepared by the following method: under the condition of the use of solvents, the flame-retardant is obtained by blending organic amino compounds, organic compounds containing phosphorus-hydrogen bonds, and aldehyde (ketone) compounds containing at least one phenolic hydroxyl group in its molecular structure to initiate the one-step reaction; the said organic amino compounds are small-molecule amino compounds, linear amino polymers, comb-like amino macromolecules, amino dendrimers or composite amino materials.

11. The highly flame-retardant adhesive for high-polymer materials according to claim 10, characterized in that the said organic amino compounds are ammonipropyl-terminated disiloxanes, fluorene ring compounds with amino as end groups, ethidene diamine, aminopropyl terminated polysiloxanes, polysiloxanes with aminopropyls on side chains, hexamethylenediamines, aminopropyltrimethoxysilanes, aminopropyl-vinyl-diethoxylsilane, aminopropyl-dimethyl-monoethoxysilane or aminopropyl-triethoxysilane; the said organic compounds containing phosphorus-hydrogen bonds are di-tert-butylphosphines, diphenylphosphine oxides, dibenzyl phosphites, dibutyl phosphites or 9, 10-dihydro-9-oxa-10-phosphena nthrene-10-oxides; the said aldehyde (ketone) compounds containing at least one phenolic hydroxyl group in the molecular structure are p-hydroxy benzaldehyde, 3, 4-dihydroxy benzaldehyde, or 2, 4-dihydroxy benzaldehyde or phloroglucinol carboxaldehyde.

12. The highly flame-retardant adhesive for high-polymer materials according to claim 10, characterized in that the said solvents are methylbenzene, tetrahydrofuran, chloroform, methyl alcohol, ethyl alcohol, diphenyl ether, dimethyl sulfoxide, or N, N-dimethylformamide.

13. The highly flame-retardant adhesive for high-polymer materials according to claim 10, characterized in that the said organic amino compounds, organic compounds containing phosphorus-hydrogen bonds and aldehyde (ketone) compounds containing at least one phenolic hydroxyl group in the molecular structure have a mole ratio of 1:(0.1-15):(0.1-20).

14. The highly flame-retardant adhesive for high-polymer materials according to claim 10, characterized in that the said organic amino compounds, organic compounds containing phosphorus-hydrogen bonds and aldehyde (ketone) compounds containing at least one phenolic hydroxyl group in the molecular structure react at the temperature of 30-180° C.

15. The highly flame-retardant adhesive for high-polymer materials according to claim 10, characterized in that the said organic amino compounds, organic compounds containing phosphorus-hydrogen bonds and aldehyde (ketone) compounds containing at least one phenolic hydroxyl group in the molecular structure react for 1-60 h.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0038] FIG. 1 is the infrared spectrogram of the flame retardant containing phenolic hydroxyl groups synthesized in Embodiment 2.

[0039] FIG. 2 is the hydrogen nuclear magnetic resonance spectrogram of the flame retardant containing phenolic hydroxyl groups synthesized in Embodiment 2.

[0040] FIG. 3 shows the data curves of the adhesives with different compositions as tested by a micro calorimeter in Test Example 13.

[0041] FIG. 4 shows the TGA data curves of adhesives with different compositions in Test Example 13.

DETAILED EMBODIMENTS

[0042] The invention is further described in combination with Embodiments as follows, but is not limited to that.

[0043] All raw materials used in the embodiments are conventional raw materials available on the market or synthesized according to the methods in the references.

[0044] The said mole ratios in the embodiments are ratios of substance quantities and the said portion ratios are mass ratios.

Embodiment 1

[0045] Mix the aminopropyl terminated disiloxane, phloroglucinol carboxaldehyde and di-tert-butylphosphine into the chloroform uniformly by the mole ratio of 1:10:4 and magnetically stir the mixture for 6 hours while maintaining the temperature at 80° C. Purify the mixture to get the phenolic hydroxyl flame retardant, with a yield of 85%.

Embodiment 2

[0046] As described in Embodiment 1, with the following differences: change aminopropyl terminated disiloxane to a fluorene ring compound with amino as end groups, di-tert-butylphosphine to DOPO, phloroglucinol carboxaldehyde to p-hydroxy benzaldehyde and the mole ratio to 1:2:2. Change the reaction temperature to 70° C. and the duration of magnetic stirring to 5 hours to get the flame-retardant with phenolic hydroxyl groups at both ends, with a reaction yield of 97%, and denote it as DFD.

[0047] The IR characterization of the phenolic hydroxyl flame-retardant synthesized in this embodiment is shown in FIG. 1. As can be seen from FIG. 1, the peak at 912 cm.sup.−1 is the infrared absorption peak of the benzene ring unsaturated carbon, and the peak at 1210 cm.sup.−1 is the stretching vibration peak of C—N;

[0048] The NMR characterization of the phenolic hydroxyl flame-retardant synthesized in this embodiment is shown in FIG. 2: .sup.1HNMR (DMSO-d.sub.6): δ (ppm) 3.38 (s, H.sub.2O), 4.78 (s, 2H, -ph-CH—NH—), 5.28 (s, 2H, —CH—NH-ph), 6.11-8.22 (8H, Ar—H), 9.38 (s, 2H, —OH).

[0049] The reaction process of the flame-retardant with phenolic hydroxyl groups at both ends obtained in this embodiment is shown in Formula (2):

##STR00002##

Embodiment 3

[0050] As described in Embodiment 2, with the following differences: change fluorene ring compound with amino as end groups to ethanediamine and remain other parameters the same to get a flame retardant with phenolic hydroxyl groups at both ends, with a reaction yield of 100%.

Embodiment 4

[0051] As described in Embodiment 3, with the following differences: change ethanediamine to aminopropyl terminated polysiloxane (with the number-average molar mass of 10000) to get a flame retardant with phenolic hydroxyl groups at both ends, with a reaction yield of 100%.

Embodiment 5

[0052] As described in Embodiment 3, with the following differences: change ethanediamine to polysiloxane with aminopropyls on side chains (the chain link content of aminopropyls in the polysiloxane is 5%, with the number-average molar mass of 120000) to get polysiloxane with phenolic hydroxyl groups on side chains finally, with a reaction yield of 90%.

Embodiment 6

[0053] As described in Embodiment 3, with the following differences: change ethanediamine to hexamethylenediamine to get a flame retardant with phenolic hydroxyl groups at both ends of the molecule, with a reaction yield of 96%.

Embodiment 7

[0054] As described in Embodiment 6, with the following differences: change hexamethylenediamine to aminopropyltrimethoxysilane to get a flame retardant with phenolic hydroxyl groups at one end, with a reaction yield of 96%.

Embodiment 8

[0055] As described in Embodiment 7, with the following differences: change aminopropyltrimethoxysilane to aminopropyl-vinyl-diethoxylsilane to get a flame retardant with vinyl-diethoxylsilane at one end, with a reaction yield of 98%.

Embodiment 9

[0056] As described in Embodiment 8, with the following differences: change aminopropyl-vinyl-diethoxylsilane to aminopropyl-dimethyl-monoethoxysilane, DOPO to 3, 4-dihydroxy benzaldehyde and the solvent to tetrahydrofuran. The product is a dimethyl-monoethoxysilane flame retardant with phenolic hydroxyl groups at one end, with a reaction yield of 95%.

Embodiment 10

[0057] As described in Embodiment 8, with the following differences: change aminopropyl-vinyl-diethoxylsilane to aminopropyl-dimethyl-monoethoxysilane, DOPO to 2, 4-dihydroxy benzaldehyde and the solvent to methylbenzene. The product is a dimethyl-monoethoxysilane flame retardant with phenolic hydroxyl groups at one end, with a reaction yield of 93%.

Embodiment 11

[0058] As described in Embodiment 8, with the following differences: change aminopropyl-vinyl-diethoxylsilane to aminopropyl-triethoxysilane, p-hydroxyl-benzophenone to salicylaldehyde and the solvent to chloroform. The product is triethoxysilane containing benzoxazine groups, with a reaction yield of 96%.

Embodiment 12

[0059] As described in Embodiment 3, with the following differences: add acetic acid as a catalyst for the reaction whose amount is 5% of that of the ethanediamine. The reaction lasts for 3 hours. The product is a flame retardant with phenolic hydroxyl groups at both ends, with a reaction yield of 94%.

Embodiment 13

[0060] Add the flame retardant with phenolic hydroxyl groups at both ends obtained in Embodiment 2 into 100 parts of base adhesive by parts of 2, 4, 6, and 8 respectively, and the said base adhesive is benzoxazine adhesive (denoted as G1). Coat the mixtures on high polymer material plates and carry out thermo-curing at certain conditions (the curing conditions are heating at 80° C., 90° C., 100° C. and 120° C. for 2 h, respectively). Place the plates for 1 day after curing to get flame-retardant adhesives denoted as G1-DFD-2, G1-DFD-4, G1-DFD-6 and G1-DFD-8, respectively. Then, determine their properties with a tensile machine.

Embodiment 14

[0061] Taking the adhesives added with flame retardant prepared in Embodiment 13 as the basic formula (100 parts), add 5 parts of fumed silica and 1 part of iron oxide red and mix them evenly; coat the mixtures on high polymer material plates and carry out thermo-curing at certain conditions (the curing conditions are heating at 80° C., 90° C., 100° C. and 120° C. for 2 h, respectively). Place the plates for 1 day after curing. Then, determine their properties with a tensile machine.

Embodiment 15

[0062] Coat the adhesives added with flame retardant obtained in Embodiment 13 on high polymer material plates and carry out thermo-curing at certain conditions (the curing conditions are heating at 120° C., 140° C. and 160° C. for 2 h, respectively). Place the plates for 1 day after curing. Then, determine their properties with a tensile machine.

Embodiment 16

[0063] Taking the adhesives added with flame retardant obtained in Embodiment 13 as the basic formula, add acetic acid, silazane treated M-5 type white carbon black (15 parts) and silane coupling agent KH570 (3 parts) and mix them evenly; coat the mixtures on steel plates evenly and carry out thermo-curing at certain conditions (the curing conditions are heating at 80° C., 90° C., 100° C. and 120° C. for 2 h, respectively). Place the plates for 1 day after curing. Then, determine their properties with a tensile machine.

Test Example 1

[0064] Test the adhesion strength of the adhesives prepared in Embodiments 13, 14 and 16. The data results are shown in Table 1.

TABLE-US-00001 TABLE 1 Adhesion strength MPa S/N 1 2 3 Average value Embodiment 13 4.34 4.42 4.83 4.53 G1-DFD-8 Embodiment 14 4.18 4.29 4.25 4.24 Embodiment 16 4.22 4.26 4.42 4.30 Comparative — — — 4.30 Example 1* *Note: the data of the Comparative Example 1 is cited from the patent numbered CN109880541A.

Test Example 2

[0065] Test the products in Embodiment 13 with a micro calorimeter to get the data. The results are shown in Table 2 and FIG. 3.

TABLE-US-00002 TABLE 2 S/N pHRR/Wg.sup.−1a THR/KJg.sup.−1b HRC/Jg.sup.−1K.sup.−1c G1 99.01 25.4 112 G1-DFD-2 97.15 23.1 109 G1-DFD-4 86.59 20.6 97 G1-DFD-6 78.43 20.8 89 G1-DFD-8 73.69 19.8 83 Comparative 102 4.6 118 Example 2* *Note: the data of Comparative Example 2 is cited from the literature (DOI: 10.1016/j.j aap. 2011.01.012).

Test Example 3

[0066] Test the products in Embodiment 13 to get the thermal stability data. The results are shown in Table 3 and FIG. 4.

TABLE-US-00003 TABLE 3 T5% (° C.) T10% (° C.) Char yield (%) G1 238 274 52.1 G1-DFD-2 245 276 52.4 G1-DFD-4 251 289 52.8 G1-DFD-6 237 284 54.2 G1-DFD-8 242 281 48.1 Comparative 283 — 45 Example 3* *Note: the data of Comparative Example 3 is cited from the patent numbered CN101220152A.

[0067] As can be seen from Table 1, the highly flame-retardant adhesive prepared in the invention can be used as an adhesive directly and has high strength; the highly flame-retardant adhesive still has good performance after being mixed with other fillers and auxiliaries, and its overall adhesion strength is even higher than the tensile strength data of coatings for high-polymer materials reported in the literature. The data shows that the adhesive in the invention has obvious superiority in performance, which further demonstrates the creativity of the invention, combining with the superiority in the preparation technology of the invention as said above.

[0068] Table 2, FIG. 3, Table 3 and FIG. 4 prove that the flame-retardant adhesive in the invention has good flame retardance and carbon residue and the properties of the base adhesive are further optimized. It is a kind of highly flame-retardant adhesive that is highly applicable to high-polymer materials.