A flame-retardant and antistatic hollow board packaging material and its preparation and application

Abstract

The present invention belongs to the field of polymer materials and their application technology, and discloses a flame-retardant and antistatic hollow board packaging material, as well as its preparation and application. The preparation method comprises the following steps: catalytically polymerizing an epoxysilane monomer, a methylsilane monomer, and a hydrogen silane end-capping agent to obtain a hydrogen-terminated epoxy polysiloxane; then catalytically copolymerizing the reaction with an α,ω diene to obtain an epoxy polysiloxane-modified polyolefin elastomer solution; then adding a reinforcing filler surface-modified with an aminosilane coupling agent and an antistatic agent to react; after the reaction is complete, adding a flame retardant and a foaming agent, mixing, drying, and granulating to obtain a flame-retardant and antistatic hollow board packaging material. The special material of the present invention can be used for flame retardancy, antistatic properties, and reinforcement, toughening, and blending modification of polyolefin hollow board packaging materials.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials and their applications, and particularly relates to a special material for flame-retardant and antistatic hollow board packaging material and its preparation and application. Background Art

[0002] Hollow board, also known as Wantong board or corrugated board, is a new material that is lightweight (hollow structure), non-toxic, pollution-free, waterproof, shockproof, age-resistant, corrosion-resistant, and available in a variety of colors. It is primarily made from environmentally friendly, pollution-free, recyclable thermoplastic polypropylene (PP) and polyethylene (PE) resins, along with various auxiliary materials. Compared to cardboard products, hollow board offers advantages such as moisture resistance and corrosion resistance, thus holding great promise for its application in packaging and transportation.

[0003] Hollow boards reduce density and weight by adding a foaming agent and introducing a hollow structure. However, the introduction of a hollow structure reduces strength. Strength can be improved by adding reinforcing fillers such as light calcium carbonate and reinforcing fibers. However, the addition of high levels of fillers reduces the continuity of the polyolefin matrix, making it difficult to further increase its strength. Furthermore, polyolefin materials inherently have relatively low toughness, and the reduction in toughness is particularly significant after the addition of high levels of fillers.

[0004] Masterbatch processing and filler modification techniques can improve filler-matrix compatibility. For example, patent application publication number CN118440421A describes a process for preparing an antistatic and wear-resistant plastic masterbatch. By incorporating modified carbon nanotubes, the masterbatch possesses excellent and stable antistatic properties, wear resistance, and flame retardancy. However, the preparation process for these modified carbon nanotubes is complex and costly, and their effect on improving the material's toughness is limited. Summary of the Invention

[0005] In view of the shortcomings and deficiencies of the above prior art, the primary purpose of the present invention is to provide a method for preparing a special material for flame-retardant and antistatic hollow board packaging materials.

[0006] Another object of the present invention is to provide a flame-retardant and antistatic hollow board packaging material prepared by the above method.

[0007] Another object of the present invention is to provide an application of the flame-retardant and antistatic hollow board packaging material in the preparation of hollow board packaging materials.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] A method for preparing a flame-retardant and antistatic hollow board packaging material, comprising the following steps:

[0010] (1) heating and polymerizing epoxy silane monomer, methyl silane monomer and hydrogen silane end-capping agent under silicon alkoxide catalyst conditions to obtain hydrogen-terminated epoxy polysiloxane;

[0011] (2) adding hydrogen-terminated epoxy polysiloxane and α,ω diene into an organic solvent to dissolve them, and then adding a hydrosilylation catalyst to carry out a heating copolymerization reaction to obtain an epoxy polysiloxane-modified polyolefin elastomer solution;

[0012] (3) surface-modifying the reinforcing filler and the antistatic agent with an aminosilane coupling agent to obtain an amino-modified functional additive;

[0013] (4) adding the obtained amino-modified functional additive to the epoxy polysiloxane-modified polyolefin elastomer solution of step (2) and heating and stirring for reaction; adding a flame retardant and a foaming agent after the reaction is completed, mixing evenly, drying and granulating to obtain a flame-retardant antistatic hollow board packaging material.

[0014] The epoxysilane monomer in step (1) is preferably 3-(2,3-epoxypropoxy)propylmethyldiethoxysilane (KH-563) or 3-(2,3-epoxypropoxy)propylmethyldimethoxysilane (KH-564).

[0015] The methylsilane monomer in step (1) is preferably one or more of octamethylcyclotetrasiloxane (D4), dimethyldimethoxysilane, and dimethyldiethoxysilane.

[0016] The hydrosilane capping agent in step (1) is preferably one or more of tetramethyldisiloxane (HMM), dimethylmethoxyhydrosilane, and dimethylethoxyhydrosilane.

[0017] The addition amounts of the epoxysilane monomer, methylsilane monomer and hydrogen silane capping agent in step (1) are controlled so that the weight average molecular weight of the obtained hydrogen-terminated epoxy polysiloxane is 500-3000 and the epoxy group mass percentage is 1%-10%.

[0018] The silicon alkoxide catalyst in step (1) is preferably sodium siliconate or potassium siliconate; the temperature of the heating polymerization reaction is 90-130° C., and the time is 2-8 hours.

[0019] The α,ω diene in step (2) is preferably one or more of 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,10-undecadiene, and 1,11-dodecadiene.

[0020] The molar ratio of the reaction of the hydrogen-terminated aminopolysiloxane and the α,ω diene in step (2) is 1:1-2.

[0021] The organic solvent in step (2) is preferably one or more of isopropanol, ethyl acetate, cyclohexane, and petroleum ether.

[0022] The hydrosilylation catalyst in step (2) is a chloroplatinic acid isopropanol solution; the temperature of the heating copolymerization reaction is 80-100° C., and the time is 2-8 hours.

[0023] The reinforcing filler in step (3) is preferably one or two of white carbon black and light calcium carbonate, and the amount of the reinforcing filler is 50% to 150% of the solid content of the epoxy polysiloxane modified polyolefin elastomer solution; the antistatic agent is preferably one or two of conductive fiber and carbon black, and the amount of the antistatic agent is 2% to 20% of the solid content of the epoxy polysiloxane modified polyolefin elastomer solution.

[0024] The aminosilane coupling agent in step (3) is preferably one or more of γ-aminopropyltrimethoxysilane (KH-540), γ-aminopropyltriethoxysilane (KH-550), N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane (KH-792), and N-β-(aminoethyl)-γ-aminopropyltriethoxysilane; the amount of the aminosilane coupling agent is 2% to 10% of the total mass of the reinforcing filler and the antistatic agent.

[0025] The surface modification method in step (3) can adopt conventional dry surface modification or wet surface modification in the art, which is a commonly used powder surface modification method in the art.

[0026] The temperature of the heating and stirring reaction in step (4) is 60-90° C. and the time is 1-3 hours.

[0027] The flame retardant in step (4) is preferably an organic phosphate flame retardant, and the amount of the flame retardant is 5% to 20% of the solid content of the epoxy polysiloxane modified polyolefin elastomer solution; the foaming agent is preferably one or more of azodicarbonamide, N,N-dinitrosopentamethylenetetramine, and sodium bicarbonate, and the amount of the foaming agent is 5% to 20% of the solid content of the epoxy polysiloxane modified polyolefin elastomer solution.

[0028] A special material for flame-retardant and antistatic hollow board packaging is prepared by the method.

[0029] The flame retardant and antistatic hollow board packaging material is used in the preparation of hollow board packaging materials. The application method is as follows: the flame retardant and antistatic hollow board packaging material and the polyolefin substrate are added into a mixer at a mass ratio of 20 to 60:100, mixed evenly, and then extruded into a mold for hot pressing and foaming to obtain the flame retardant and antistatic hollow board packaging material.

[0030] The polyolefin substrate is preferably polypropylene (PP) or polyethylene (PE).

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The flame-retardant and antistatic hollow board packaging material of the present invention adopts epoxy polysiloxane-modified polyolefin elastomer to coat and chemically graft-modify amino-modified reinforcing fillers and antistatic agents, which can significantly improve the dispersibility and bonding strength of the reinforcing fillers and antistatic agents in the polyolefin substrate. At the same time, the polysiloxane chain segments contained therein can significantly improve the toughness of the board, thereby achieving good reinforcing and toughening effects. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

[0034] Example 1

[0035] A method for preparing a flame-retardant and antistatic hollow board packaging material, comprising the following steps:

[0036] (1) 3-(2,3-Epoxypropyl)propylmethyldiethoxysilane (KH-563), octamethylcyclotetrasiloxane (D4), tetramethyldisiloxane (HMM), and potassium trimethylsilanol catalyst were added to a reaction flask at a mass ratio of 30:70:7:0.04 and stirred to mix evenly. Nitrogen was introduced into the reaction flask for protection. The heating mantle was heated to 110°C and stirred for polymerization for 6 hours. The temperature was then raised to 140°C and the unreacted raw materials were removed under reduced pressure to obtain hydrogen-terminated epoxy polysiloxane. The obtained product was tested to have a hydrogen content (Si-H) of 0.10%, an epoxy content of 4.96%, a theoretical molecular weight of 2000, and a yield of 87%.

[0037] (2) The hydrogen-terminated epoxy polysiloxane and 1,8-nonadiene in the step (1) were added to a reaction flask containing an isopropanol solvent in a molar ratio of 1:1.5 and mixed and dissolved. Nitrogen was introduced into the reaction flask for replacement protection. Then, a 0.01% chloroplatinic acid isopropanol solution catalyst was added, and the electric heating mantle was heated to 90° C. and stirred for polymerization reaction for 4 hours. The active hydrogen of the product was detected to be completely reacted, and an epoxy polysiloxane-modified polyolefin elastomer solution with a solid content of 25% was obtained.

[0038] (3) By weight, 100 parts of reinforcing filler silica and 10 parts of carbon fiber powder antistatic agent were mixed, and then 6 parts of aminosilane coupling agent KH-540 were used for dry surface modification to obtain an amino-modified functional additive.

[0039] (4) The obtained amino-modified functional additive is added to 400 parts of the epoxy polysiloxane-modified polyolefin elastomer solution of step (2) and dispersed evenly, heated to 80° C. and stirred for reaction for 2 hours. After the reaction is completed, 10 parts of flame retardant tris(2-chloropropyl) phosphate (TCPP) and 10 parts of foaming agent azodicarbonamide are added and mixed evenly, and vacuum dried and granulated to obtain a special material for flame retardant and antistatic hollow board packaging material.

[0040] Example 2

[0041] A method for preparing a flame-retardant and antistatic hollow board packaging material, comprising the following steps:

[0042] (1) 3-(2,3-Epoxypropyl)propylmethyldimethoxysilane (KH-564), octamethylcyclotetrasiloxane (D4), tetramethyldisiloxane (HMM), and potassium trimethylsilanol catalyst were added to a reaction flask in a mass ratio of 40:60:12:0.04 and stirred to mix evenly. Nitrogen was introduced into the reaction flask for protection. The heating mantle was heated to 110°C and stirred for polymerization for 6 hours. The temperature was then raised to 140°C and the unreacted raw materials were removed under reduced pressure to obtain hydrogen-terminated epoxy polysiloxane. The hydrogen content (Si-H) of the obtained product was 0.15%, the epoxy content was 6.65%, the theoretical molecular weight was 1333, and the yield was 82%.

[0043] (2) The hydrogen-terminated epoxy polysiloxane of step (1) and 1,7-octadiene were added to a reaction flask containing isopropanol solvent in a molar ratio of 1:1.8, and mixed and dissolved. Nitrogen was introduced into the reaction flask for replacement protection. Then, a 0.01% chloroplatinic acid isopropanol solution catalyst was added, and the electric heating mantle was heated to 90° C. and stirred for polymerization reaction for 4 hours. The active hydrogen of the product was detected to be completely reacted, and an epoxy polysiloxane-modified polyolefin elastomer solution with a solid content of 25% was obtained.

[0044] (3) By weight, 150 parts of reinforcing filler white carbon black and 20 parts of carbon fiber powder antistatic agent were mixed and then dry-surface modified with 10 parts of aminosilane coupling agent KH-540 to obtain an amino-modified functional additive.

[0045] (4) The obtained amino-modified functional additive is added to 400 parts of the epoxy polysiloxane-modified polyolefin elastomer solution of step (2) and dispersed evenly, heated to 80° C. and stirred for reaction for 2 hours. After the reaction is completed, 10 parts of flame retardant tris(2-chloropropyl) phosphate (TCPP) and 10 parts of foaming agent azodicarbonamide are added and mixed evenly, and vacuum dried and granulated to obtain a special material for flame retardant and antistatic hollow board packaging material.

[0046] Example 3

[0047] A method for preparing a flame-retardant and antistatic hollow board packaging material, comprising the following steps:

[0048] (1) 3-(2,3-Epoxypropyl)propylmethyldiethoxysilane (KH-563), octamethylcyclotetrasiloxane (D4), tetramethyldisiloxane (HMM), and potassium trimethylsilanol catalyst were added to a reaction flask at a mass ratio of 20:80:5:0.04 and stirred to mix evenly. Nitrogen was introduced into the reaction flask for protection. The mixture was heated to 110°C with an electric heating mantle and stirred for polymerization for 6 hours. The temperature was then raised to 140°C and the unreacted raw materials were removed under reduced pressure to obtain hydrogen-terminated epoxy polysiloxane. The hydrogen content (Si-H) of the obtained product was 0.07%, the epoxy content was 3.07%, the theoretical molecular weight was 2857, and the yield was 91%.

[0049] (2) The hydrogen-terminated epoxy polysiloxane of step (1) and 1,11-dodecadiene were added to a reaction flask containing isopropanol solvent in a molar ratio of 1:1.1 and mixed and dissolved. Nitrogen was introduced into the reaction flask for replacement protection. Then, a 0.01% chloroplatinic acid isopropanol solution catalyst was added. The electric heating mantle was heated to 90° C. and stirred for polymerization reaction for 4 hours. The active hydrogen of the product was detected to be completely reacted to obtain an epoxy polysiloxane-modified polyolefin elastomer solution with a solid content of 25%.

[0050] (3) By weight, 50 parts of reinforcing filler white carbon black and 5 parts of carbon fiber powder antistatic agent were mixed and then dry-surface modified with 3 parts of aminosilane coupling agent KH-540 to obtain an amino-modified functional additive.

[0051] (4) The obtained amino-modified functional additive is added to 400 parts of the epoxy polysiloxane-modified polyolefin elastomer solution of step (2) and dispersed evenly, heated to 80° C. and stirred for reaction for 2 hours. After the reaction is completed, 10 parts of flame retardant tris(2-chloropropyl) phosphate (TCPP) and 20 parts of foaming agent azodicarbonamide are added and mixed evenly, and vacuum dried and granulated to obtain a special material for flame retardant and antistatic hollow board packaging material.

[0052] Comparative Example 1

[0053] A method for preparing a flame-retardant and antistatic hollow board packaging material, comprising the following steps:

[0054] (1) By weight, 100 parts of reinforcing filler white carbon black and 10 parts of carbon fiber powder antistatic agent were mixed, and then 6 parts of aminosilane coupling agent KH-540 were used for dry surface modification to obtain an amino-modified functional additive.

[0055] (2) The obtained amino-modified functional additive, 100 parts of low-density polyethylene substrate (LDPE), 10 parts of flame retardant tris(2-chloropropyl) phosphate (TCPP) and 10 parts of foaming agent azodicarbonamide are added into a mixer and mixed evenly at 160-180°C, and then extruded and granulated to obtain a special material for flame-retardant and antistatic hollow board packaging materials.

[0056] Comparative Example 2

[0057] A method for preparing a flame-retardant and antistatic hollow board packaging material, comprising the following steps:

[0058] (1) Octamethylcyclotetrasiloxane (D4), tetramethyldisiloxane (HMM), and potassium trimethylsilanol catalyst were added to a reaction flask in a mass ratio of 100:7:0.04 and stirred to mix evenly. Nitrogen was introduced into the reaction flask for protection. The reaction flask was heated to 110°C with an electric heating mantle and stirred for polymerization for 6 hours. The temperature was then raised to 140°C and the unreacted raw materials were removed under reduced pressure to obtain hydrogen-terminated methyl polysiloxane. The hydrogen content (Si-H) of the obtained product was determined to be 0.10%, the theoretical molecular weight was 2000, and the yield was 89%.

[0059] The preparation process of steps (2) to (4) is the same as that of Example 1.

[0060] Example 4

[0061] The special materials (masterbatches) obtained in the above Examples 1 to 3 and Comparative Examples 1 to 2 are used in the preparation of hollow board packaging materials. The application method is as follows: the flame retardant and antistatic hollow board packaging material special material and the low-density polyethylene substrate (LDPE) are added to a mixer at a mass ratio of 30:100 and mixed evenly at 160-180°C, and then extruded into a mold and hot-pressed and foamed at 200-210°C to obtain a flame retardant and antistatic hollow board.

[0062] The mechanical properties (test thickness 2.5 mm), flame retardancy and antistatic properties (test surface resistivity) of the obtained flame retardant and antistatic hollow board were tested, and the results are shown in Table 1 below.

[0063] Table 1

[0064] performance Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Breaking strength, N 190 216 177 143 154 Elongation at break, % 223 181 254 132 238 Tearing force, N 95 104 85 51 56 Plane compression force, N 905 953 871 720 767 Vertical compression force, N 87 90 70 46 68 Flame retardant grade V-0 V-0 V-0 V-0 V-0 Surface resistivity, Ω <![CDATA[1.5×10 5 ]]> <![CDATA[8.6×10 4 ]]> <![CDATA[2.3×10 5 ]]> <![CDATA[2.4×10 5 ]]> <![CDATA[2.2×10 5 ]]>

[0065] From the comparison results of Comparative Example 1 in Table 1, it can be seen that the improvement effect of the special material (masterbatch) obtained by not using epoxy polysiloxane modified polyolefin elastomer on the mechanical properties of polyolefin hollow board materials is significantly reduced. From the comparison results of Comparative Example 2, it can be seen that the use of polysiloxane modified polyolefin elastomer without epoxy groups has a significant improvement effect on the toughness of polyolefin hollow board materials, but the improvement effect on strength is limited. In addition, from the comparison results of Example 1 and Comparative Examples 1-2, it can be seen that the introduction of epoxy polysiloxane modified polyolefin elastomer also has a certain effect on improving the antistatic properties of polyolefin hollow board materials. The reason is that the epoxy groups contained in the epoxy polysiloxane modified polyolefin elastomer can chemically connect with the antistatic agent modified by the aminosilane coupling agent, thereby improving its dispersion performance in the matrix.

[0066] The above embodiments are preferred implementations of the present invention, but the implementations of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing a flame retardant and antistatic hollow board packaging material, characterized in that: The method comprises the following preparation steps: (1) heating and polymerizing epoxy silane monomer, methyl silane monomer and hydrogen silane capping agent under silicon alkoxide catalyst to obtain hydrogen-terminated epoxy polysiloxane; (2) adding hydrogen-terminated epoxy polysiloxane and α,ω-diolefin into an organic solvent to dissolve them, and then adding a hydrosilylation catalyst to carry out a heating copolymerization reaction to obtain an epoxy polysiloxane-modified polyolefin elastomer solution; (3) The reinforcing filler and the antistatic agent are surface-modified using an aminosilane coupling agent to obtain an amino-modified functional additive; (4) adding the obtained amino-modified functional additive to the epoxy polysiloxane-modified polyolefin elastomer solution of step (2) and heating and stirring to react; after the reaction is completed, adding a flame retardant and a foaming agent and mixing evenly; drying and granulating to obtain a flame retardant and antistatic hollow board packaging material; The amount of epoxysilane monomer, methylsilane monomer and hydrogen silane capping agent added in step (1) is controlled so that the weight average molecular weight of the obtained hydrogen-terminated epoxy polysiloxane is 500-3000 and the epoxy group mass percentage is 1%-10%; The α,ω-diene in step (2) is one or more of 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,10-undecadiene, and 1,11-dodecadiene; and the molar ratio of the hydrogen-terminated epoxy polysiloxane to the α,ω-diene is 1:1-2.

2. The method for preparing a flame retardant and antistatic hollow board packaging material according to claim 1, characterized in that: In step (1), the epoxysilane monomer is 3-(2,3-epoxypropoxy)propylmethyldiethoxysilane or 3-(2,3-epoxypropoxy)propylmethyldimethoxysilane; the methylsilane monomer is one or more of octamethylcyclotetrasiloxane, dimethyldimethoxysilane, and dimethyldiethoxysilane; and the hydrogen silane capping agent is one or more of tetramethyldisiloxane, dimethylmethoxyhydrogensilane, and dimethylethoxyhydrogensilane.

3. The method for preparing a flame retardant and antistatic hollow board packaging material according to claim 1, characterized in that: The silicon alkoxide catalyst in step (1) is sodium siliconate or potassium siliconate; the temperature of the heating polymerization reaction is 90-130° C., and the time is 2-8 hours.

4. The method for preparing a flame retardant and antistatic hollow board packaging material according to claim 1, characterized in that: The organic solvent in step (2) is one or more of isopropanol, ethyl acetate, cyclohexane, and petroleum ether; the hydrosilylation catalyst is a chloroplatinic acid isopropanol solution; and the temperature of the heating copolymerization reaction is 80-100° C., and the time is 2-8 hours.

5. The method for preparing a flame retardant and antistatic hollow board packaging material according to claim 1, characterized in that: The reinforcing filler in step (3) is one or both of white carbon black and light calcium carbonate, and the amount of the reinforcing filler is 50% to 150% of the solid content of the epoxy polysiloxane modified polyolefin elastomer solution; the antistatic agent is one or both of conductive fiber and carbon black, and the amount of the antistatic agent is 2% to 20% of the solid content of the epoxy polysiloxane modified polyolefin elastomer solution; the aminosilane coupling agent is one or more of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and N-β-(aminoethyl)-γ-aminopropyltriethoxysilane; the amount of the aminosilane coupling agent is 2% to 10% of the total mass of the reinforcing filler and the antistatic agent.

6. The method for preparing a flame-retardant and antistatic hollow board packaging material according to claim 1, characterized in that: The temperature of the heating and stirring reaction in step (4) is 60-90° C., and the time is 1-3 hours; the flame retardant is an organic phosphate flame retardant, and the amount of the flame retardant is 5%-20% of the solid content of the epoxy polysiloxane modified polyolefin elastomer solution; the foaming agent is one or more of azodicarbonamide, N,N-dinitrosopentamethylenetetramine, and sodium bicarbonate, and the amount of the foaming agent is 5%-20% of the solid content of the epoxy polysiloxane modified polyolefin elastomer solution.

7. A flame retardant and antistatic hollow board packaging material, characterized in that: It is prepared by the method according to any one of claims 1 to 6.

8. Use of the flame-retardant and antistatic hollow board packaging material according to claim 7 in the preparation of hollow board packaging materials, characterized in that: The application method comprises the following steps: adding a flame-retardant antistatic hollow board packaging material special material and a polyolefin base material in a mass ratio of 20-60:100 into a mixer, kneading the mixture evenly, and then extruding the mixture into a mold for hot pressing and foaming to obtain the flame-retardant antistatic hollow board packaging material.