Application of tin bismuth oxide as flame retardant

Abstract

The present invention relates to a tin-bismuth oxide (including Bi 2 Sn 2 O 7 ,Bi 2 Sn 3 O 9 ) as a flame retardant. The tin-bismuth oxide is used as a flame retardant for polymers such as soft polyvinyl chloride, and its amount accounts for 0.1%-10% of the mass of the polymer. The present application has found that tin-bismuth oxide, as a flame retardant for polymers (such as lightweight polyvinyl chloride), has flame retardant properties and smoke suppression effects comparable to antimony oxide, and can completely replace antimony oxide.

Description

Technical Field

[0001] The invention belongs to the technical field of flame retardancy, and specifically discloses an application of tin-bismuth oxide as a flame retardant, and an inorganic compound containing tin-bismuth oxide and having a flame retardant function. Background Art

[0002] As we all know, polyvinyl chloride (abbreviated as PVC) contains a large amount of chlorine (56.7% by mass). During the combustion process, a large amount of hydrogen chloride is produced, which can effectively prevent combustion by isolating the air. Therefore, rigid polyvinyl chloride is not flammable. Soft polyvinyl chloride is different. Since a large amount of small molecular organic matter is added to polyvinyl chloride as a plasticizer, polyvinyl chloride is flammable. For polyvinyl chloride, among many flame retardants, due to the synergistic flame retardant properties of antimony and chlorine, antimony oxide shows excellent flame retardant properties for chlorine-containing polymers and has a certain smoke suppression effect. Therefore, antimony oxide (Sb2O3, Sb2O5) is currently the most effective flame retardant for polyvinyl chloride in industry. However, since antimony oxide itself is toxic, it will release toxic and irritating gases under combustion conditions, which will cause respiratory diseases and cardiovascular diseases and cause environmental damage. At the same time, the content of antimony in the earth's crust is low, and its price is also increasing year by year. Under the premise that the country pays more and more attention to environmental protection, it is very urgent and necessary to seek its substitutes. Summary of the invention

[0003] The present invention aims to overcome the defects of the prior art and provide an application of tin-bismuth oxide as a flame retardant, and an inorganic compound containing tin-bismuth oxide and having a flame retardant function. As a polymer flame retardant, tin-bismuth oxide has flame retardant properties and smoke suppression effects comparable to those of antimony oxide, and can be used as a candidate material to replace antimony oxide.

[0004] To achieve the above object, the present invention adopts the following technical solution:

[0005] The invention provides application of tin-bismuth oxide as a flame retardant.

[0006] Specifically, the tin-bismuth oxide may be Bi2Sn2O7 and / or Bi2Sn3O9, etc.

[0007] Furthermore, the present invention provides the tin-bismuth oxide as a flame retardant for use in polymers, such as soft polyvinyl chloride, etc. for flame retardancy.

[0008] Specifically, in the above application, the amount of tin-bismuth oxide used accounts for 0.1%-10% of the mass of soft polyvinyl chloride.

[0009] In the soft polyvinyl chloride formula, the organic plasticizer is not limited to dioctyl phthalate (DOP), and can include other plasticizers recognized by the polyvinyl chloride industry, such as aliphatic esters, polyesters, phosphate esters, epoxy oils, etc.

[0010] Specifically, the soft polyvinyl chloride comprises 100 parts of polyvinyl chloride resin, 10-100 parts of dioctyl phthalate, and 0.2-2.2 parts of stearic acid compound, in parts by mass. The tin-bismuth oxide of the present invention has excellent flame retardant properties for chlorine-containing polymers.

[0011] Specifically, the stearic acid compound may be one or more of calcium stearate, lead stearate, stearic acid, and the like.

[0012] Furthermore, the soft polyvinyl chloride may include, by weight, 100 parts of polyvinyl chloride resin, 10-100 parts of dioctyl phthalate, 0.2-0.6 parts of calcium stearate, 0.2-0.6 parts of lead stearate, and 0.2-1.0 parts of stearic acid.

[0013] Further preferably, the soft polyvinyl chloride may include, by weight, 100 parts of polyvinyl chloride resin, 40 parts of dioctyl phthalate, 0.4 parts of calcium stearate, 0.4 parts of lead stearate, and 0.8 parts of stearic acid.

[0014] The present invention provides an inorganic compound with flame retardant function. Specifically, the inorganic compound is tin bismuth oxide Bi2Sn2O7 and / or Bi2Sn3O9.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] Tin bismuth oxide (such as bismuth stannate) has been widely studied as a photocatalyst and can be used in many chemical reactions and as a photocatalyst, but it has not yet been found to be used in the field of flame retardancy. In the field of flame retardancy, tin-containing compounds (such as tin oxide, zinc stannate, etc.) as substitutes for antimony oxide have obvious flame retardant and smoke suppression effects, while bismuth, as a homologous element of antimony, has lower toxicity and lower price. The present application has found through research that tin bismuth oxide as a flame retardant for polymers (such as lightweight polyvinyl chloride) has flame retardant properties and smoke suppression effects comparable to antimony oxide, and can completely replace antimony oxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 XRD diagram of Bi2Sn2O7 synthesized by the present invention;

[0018] Figure 2 It is a comparison curve of peak heat release of different contents of Bi2Sn2O7 and antimony oxide in soft PVC;

[0019] Figure 3 This is a comparison curve of total smoke release during combustion of different contents of Bi2Sn2O7 and antimony oxide in soft PVC. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is further described in detail below in conjunction with the embodiments, but the protection scope of the present invention is not limited thereto.

[0021] The tin-bismuth oxides Bi2Sn2O7 and Bi2Sn3O9 (CAS No. 12338-09-9 and 12010-67-2, respectively) mentioned in the present invention can be directly purchased from ordinary commercial products, or can be prepared by conventional methods in the art. For example, the synthesis method of Bi2Sn2O7 is as follows:

[0022] Dissolve 100 parts by mass of SnCl4 5H2O and 90 parts by mass of BiCl3 in 100 mL of 1 mol / L hydrochloric acid. After complete dissolution, add an appropriate amount of 7 mol / L ammonia water to the above solution to adjust the pH to neutral for coprecipitation. Filter and wash the above product until no chloride ions are detected in the filtrate. The filter cake is dried in a conventional oven at 80 o C and dried at 600 o The bismuth stannate product Bi2Sn2O7 was obtained by annealing in a muffle furnace at 400 °C for 2 hours.

[0023] Figure 1 This is the XRD diagram of Bi2Sn2O7 synthesized by the present invention; the figure confirms that it matches the Bi2Sn2O7 of the standard card PDF#87-0284 and is a pure phase of Bi2Sn2O7.

[0024] Example 1

[0025] An inorganic compound with flame retardant function: 40 parts by mass of dioctyl phthalate (DOP), 0.4 parts by mass of calcium stearate, 0.4 parts by mass of lead stearate, and 0.8 parts by mass of stearic acid are added to every 100 parts by mass of polyvinyl chloride resin to form soft polyvinyl chloride, and 1.43 parts by mass of flame retardant Bi2Sn2O7 is added.

[0026] Example 2

[0027] An inorganic compound with flame retardant function: 40 parts by mass of dioctyl phthalate (DOP), 0.4 parts by mass of calcium stearate, 0.4 parts by mass of lead stearate, and 0.8 parts by mass of stearic acid are added to every 100 parts by mass of polyvinyl chloride resin to form soft polyvinyl chloride, and 4.38 parts by mass of flame retardant Bi2Sn2O7 is added.

[0028] Example 3

[0029] An inorganic compound with flame retardant function: 40 parts by mass of dioctyl phthalate (DOP), 0.4 parts by mass of calcium stearate, 0.4 parts by mass of lead stearate and 0.8 parts by mass of stearic acid are added to every 100 parts by mass of polyvinyl chloride resin to form soft polyvinyl chloride, and 7.45 parts by mass of flame retardant Bi2Sn2O7 is added.

[0030] Comparative Example 1

[0031] A flame retardant inorganic compound: 40 parts by mass of dioctyl phthalate (DOP), 0.4 parts by mass of calcium stearate, 0.4 parts by mass of lead stearate, and 0.8 parts by mass of stearic acid are added to every 100 parts by mass of polyvinyl chloride resin to form soft polyvinyl chloride, and 4.38 parts by mass of flame retardant Sb2O3 is added.

[0032] The preparation method of the test sample of the inorganic compound composed of the flame retardant and soft polyvinyl chloride is as follows:

[0033] After fully mixing the raw materials in the above embodiments or comparative examples according to different proportions, mix them on a double-roll open mill at 110°C for 10 minutes. Then transfer the sample to a flat vulcanizer and gradually increase the pressure from normal pressure to 23 MPa at 170°C for vulcanization for 10 minutes. After calendering (conventional technology in the art can be used, which is not the innovation of this application, so it will not be repeated here), cool to room temperature, and cut into different test specimens by a cutting machine for flame retardant performance tests such as vertical burning parameters (UL-94) and limiting oxygen index (LOI). The results are shown in Table 1.

[0034] Table 1 Vertical combustion parameters (UL-94) and limiting oxygen index (LOI) of different contents of Bi2Sn2O7 in soft PVC

[0035]

[0036] It can be seen from the experimental results in Table 1 that when the flame retardant Bi2Sn2O7 of Example 2 of the present invention is compared with the antimony oxide Sb2O3 of Comparative Example 1, when the addition amount in soft PVC is 3% (mass ratio), the limiting oxygen index (LOI) of the inorganic material of the present invention is slightly lower than that of antimony oxide, but the inorganic material of the present invention can pass the V0 level of the vertical combustion parameter (UL-94) and no molten drop phenomenon occurs, which can avoid the risk of secondary fire. However, antimony oxide does not obtain the vertical combustion level and has a molten drop phenomenon. It shows that the inorganic material of the present invention has good flame retardant properties and can be used as a candidate material for antimony oxide.

[0037] Figure 2 The peak heat release comparison curves of different contents of Bi2Sn2O7 and antimony oxide in soft PVC are given; Figure 2It can be seen that different contents of the inorganic substances of the present invention can reduce the peak heat release of soft PVC. At the same addition amount of 3% (mass ratio), the peak heat release of Bi2Sn2O7 of the present invention is lower than that of antimony oxide.

[0038] Figure 3 A comparison curve of total smoke release from combustion of different contents of Bi2Sn2O7 and antimony oxide in soft PVC is given. Figure 3 It can be seen that different contents of the inorganic substances of the present invention all have obvious smoke suppression performance. At the same addition amount of 3% (mass ratio), the Bi2Sn2O7 of the present invention has comparable smoke suppression performance with antimony oxide.

[0039] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes based on the present invention, such as surface modification, introduction of other components, etc., which should all fall within the scope of protection granted by the claims of the present invention.

Claims

1. Application of tin-bismuth oxide as a flame retardant, characterized in that: The tin-bismuth oxide is Bi2Sn2O7 and / or Bi2Sn3O9; The tin-bismuth oxide is used as a flame retardant for flame retardancy of polymers.

2. The use according to claim 1, characterized in that The tin-bismuth oxide is used as a flame retardant for flame retardant of soft polyvinyl chloride, and the amount of the tin-bismuth oxide is 0.1%-10% of the mass of the soft polyvinyl chloride.

3. The use according to claim 2, characterized in that In parts by mass, the soft polyvinyl chloride comprises 100 parts of polyvinyl chloride resin, 10-100 parts of dioctyl phthalate, and 0.2-2.2 parts of stearic acid compound.

4. The use according to claim 3, characterized in that The stearic acid compound is one or more of calcium stearate, lead stearate and stearic acid.

5. The use according to claim 4, characterized in that In parts by mass, the soft polyvinyl chloride comprises 100 parts of polyvinyl chloride resin, 10-100 parts of dioctyl phthalate, 0.2-0.6 parts of calcium stearate, 0.2-0.6 parts of lead stearate, and 0.2-1.0 parts of stearic acid.

6. The use according to claim 4, characterized in that In parts by mass, the soft polyvinyl chloride includes 100 parts of polyvinyl chloride resin, 40 parts of dioctyl phthalate, 0.4 parts of calcium stearate, 0.4 parts of lead stearate, and 0.8 parts of stearic acid.

Images