A high-strength calcium plastic sheet and its preparation method and application

Abstract

The present invention belongs to the technical field of polymer materials, and discloses a high-strength calcium plastic sheet and its preparation method and application. The high-strength calcium plastic sheet comprises the following raw material components by weight: 80-100 parts of polyolefin, 20-60 parts of epoxy group-modified calcium carbonate, 5-20 parts of amino polysiloxane-modified polyolefin elastomer, and 1-8 parts of foaming agent. The amino polysiloxane-modified polyolefin elastomer is obtained by addition copolymerization of hydrogen-terminated amino polysiloxane and α,ω-diene. The present invention uses the amino polysiloxane-modified polyolefin elastomer to modify the polyolefin material. The carbon chain hard segments contained therein can significantly enhance the compatibility and binding force with the polyolefin material. At the same time, the polysiloxane chain soft segments contained therein can significantly improve the toughness of the sheet, and the amino groups contained therein can carry out chemical cross-linking reactions with the epoxy group-modified calcium carbonate during the mixing process and the hot pressing and foaming process, thereby significantly improving the strength of the sheet.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and particularly relates to a high-strength calcium plastic board and its preparation method and application. Background Art

[0002] Calcium plastic board refers to a board made from polyolefin as the base material, adding a large amount of light calcium carbonate and a small amount of additives through processes such as plastic refining, hot pressing, and foaming. This kind of board has the characteristics of light weight, sound insulation, heat insulation, moisture resistance, can be recycled multiple times, and is pressure-resistant and abrasion-resistant (10 - 20 times that of ordinary corrugated cardboard boxes), and is widely used in the fields of building decoration and packaging materials.

[0003] The patent application document with the publication number CN 104295037A discloses a heat-insulating and sound-insulating calcium plastic board, and its substrate layer is composed of the following raw materials in parts by weight: 80 - 100 parts of high-pressure polyethylene resin, 20 - 35 parts of light calcium carbonate, 1 - 2.5 parts of foaming agent, 2.5 - 4 parts of cross-linking agent, and 2 - 3.5 parts of wood cellulose. The patent application document with the publication number CN 105061864A discloses an LDPE high-foaming calcium plastic board, and the raw material composition is: 70 - 100 parts of LDPE, 1 - 5 parts of HDPE, 100 - 120 parts of light calcium carbonate, 7 - 9 parts of foaming agent, 0.7 - 0.8 parts of DCP cross-linking agent, 1 - 2 parts of tribasic lead sulfate, and 2 - 3 parts of zinc stearate.

[0004] In the composition of existing calcium plastic boards, due to the addition of a high content of light calcium carbonate, the continuity of the polyolefin matrix is reduced, so it is difficult to further improve its strength. At the same time, the polyolefin material itself has slightly poor toughness, and after adding a high content of light calcium carbonate, its toughness decreases particularly significantly. The patent application document with the publication number CN 115197494A discloses a high-density polyethylene high-thermal-conductivity composite material, which uses hydroxy silicone resin to toughen high-density polyethylene and can reduce the crystallinity of high-density polyethylene. However, it is found in actual applications that the compatibility between hydroxy silicone resin and polyethylene materials is poor and it is difficult to be mixed into an ideal homogeneous phase. Although it can improve the toughness of the material to a certain extent, it will significantly reduce the material strength and is not suitable for applications in calcium plastic board products with high strength requirements. Summary of the Invention

[0005] Aiming at the above-mentioned shortcomings and deficiencies of the prior art, the primary object of the present invention is to provide a high-strength calcium plastic board.

[0006] Another object of the present invention is to provide a preparation method for the above-mentioned high-strength calcium plastic board.

[0007] Another object of the present invention is to provide the application of the above-mentioned high-strength calcium plastic board in the preparation of packing boxes.

[0008] The object of the present invention is achieved by the following technical solutions:

[0009] A high-strength calcium plastic sheet, comprising the following raw materials by weight parts:

[0010] 80 - 100 parts of polyolefin, 20 - 60 parts of epoxy group modified calcium carbonate, 5 - 20 parts of amino polysiloxane modified polyolefin elastomer, 1 - 8 parts of foaming agent;

[0011] The amino polysiloxane modified polyolefin elastomer is prepared by the following method:

[0012] (1) Heat and polymerize amino silane monomer, methyl silane monomer and hydrogen silane end-capping agent under the condition of catalyst to obtain hydrogen end-capped amino polysiloxane;

[0013] (2) Dissolve hydrogen end-capped amino polysiloxane and α,ω-diene in an organic solvent, then add a hydrosilylation catalyst and carry out heating copolymerization reaction. After the reaction is completed, dry and granulate to obtain amino polysiloxane modified polyolefin elastomer.

[0014] The polyolefin is preferably polyethylene (PE) or polypropylene (PP).

[0015] The epoxy group modified calcium carbonate is preferably epoxy group modified calcium carbonate surface-modified by epoxy group silane coupling agent KH-560 (γ-glycidoxypropyltrimethoxysilane) or KH-561 (γ-glycidoxypropyltriethoxysilane). The surface modification method can adopt the conventional dry surface modification or wet surface modification in the art, which is a commonly used powder surface modification method in the art.

[0016] The foaming agent is preferably one or more of azodicarbonamide, N,N-dinitrosopentamethylenetetramine, sodium bicarbonate, ammonium bicarbonate.

[0017] In step (1), the amino silane monomer is preferably one or more of γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane (KBE-902), N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane (KH-602), N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane.

[0018] In step (1), the methyl silane monomer is preferably one or more of octamethylcyclotetrasiloxane (D4), dimethyldimethoxysilane, dimethyldiethoxysilane.

[0019] In step (1), the hydrogen silane end-capping agent is preferably one or more of tetramethyldisiloxane (HMM), dimethylmethoxyhydrogen silane, dimethylethoxyhydrogen silane.

[0020] The addition amounts of the amino silane monomer, methyl silane monomer and hydrosilane end-capping agent described in step (1) are controlled so that the weight-average molecular weight of the hydrogen-terminated amino polysiloxane obtained is 500 to 3000, and the mass percentage of amino groups is 0.5% to 5%.

[0021] The catalyst described in step (1) is preferably at least one of sodium hydroxide, potassium hydroxide, sodium silanolate, potassium silanolate, and tetramethylammonium hydroxide; the temperature of the heating polymerization reaction is 80 to 140 °C, and the time is 2 to 8 h.

[0022] The α,ω-diene described 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.

[0023] The molar ratio of the hydrogen-terminated amino polysiloxane to the α,ω-diene in the reaction in step (2) is 1:1 to 2.

[0024] The organic solvent described in step (2) is one or more of isopropyl alcohol, ethyl acetate, cyclohexane, and petroleum ether.

[0025] The hydrosilylation catalyst described in step (2) is an isopropyl alcohol solution of chloroplatinic acid; the temperature of the heating copolymerization reaction is 80 to 100 °C, and the time is 2 to 8 h.

[0026] The preparation method of the above-mentioned high-strength calcium plastic sheet includes the following preparation steps:

[0027] Mix the amino polysiloxane-modified polyolefin elastomer, epoxy group-modified calcium carbonate, polyolefin material and foaming agent, then add them to a mixer and mix evenly, and then extrude them into a mold for hot pressing and foaming to form a high-strength calcium plastic sheet.

[0028] Application of the above-mentioned high-strength calcium plastic sheet in the preparation of packaging boxes.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] The calcium plastic sheet of the present invention uses an amino polysiloxane-modified polyolefin elastomer to modify the polyolefin material. The carbon chain hard segments contained therein can significantly enhance the compatibility and bonding force with the polyolefin material. At the same time, the polysiloxane chain soft segments contained therein can significantly improve the toughness of the sheet. Further, epoxy group-modified calcium carbonate is used, which can carry out chemical cross-linking reactions with the amino groups on the amino polysiloxane-modified polyolefin elastomer during the mixing process and the hot pressing and foaming process, thereby significantly improving the strength of the sheet. Specific Embodiments

[0031] The following further describes the present invention in detail with reference to embodiments, but the embodiments of the present invention are not limited thereto.

[0032] Example 1

[0033] A preparation method of a high-strength calcium plastic sheet, comprising the following preparation steps:

[0034] (1) γ-aminopropylmethyldiethoxysilane (KBE-902), octamethylcyclotetrasiloxane (D4), tetramethyldisiloxane (HMM) and tetramethylammonium hydroxide catalyst were added to a reaction flask in a mass ratio of 30:70:7:0.05, stirred and mixed evenly. Nitrogen was introduced into the reaction flask for replacement protection, and the mixture was heated to 90 °C with an electric heating mantle and stirred for polymerization reaction for 4 h. Then the temperature was raised to 140 °C to decompose and remove the catalyst and unreacted raw materials under reduced pressure, and a hydrogen-terminated amino polysiloxane was obtained. The hydrogen content (Si-H) of the obtained product was detected to be 0.11%, the amino content was 2.65%, the theoretical molecular weight was 1818, and the yield was 86%.

[0035] (2) The hydrogen-terminated amino polysiloxane from step (1) and 1,8-nonadiene were added to a reaction flask containing isopropanol solvent in a molar ratio of 1:1.5, mixed and dissolved. Nitrogen was introduced into the reaction flask for replacement protection, and then 0.01% chloroplatinic acid isopropanol solution catalyst was added. The mixture was heated to 90 °C with an electric heating mantle and stirred for polymerization reaction for 4 h. After detecting that the active hydrogen reaction of the product was complete, the reaction solution was input into a drying granulator for drying and granulation to obtain an amino polysiloxane-modified polyolefin elastomer.

[0036] (3) Light calcium carbonate was surface-modified by dry method with 5% epoxy group silane coupling agent KH-560 to obtain epoxy group-modified calcium carbonate.

[0037] (4) 100 parts by weight of low-density polyethylene (LDPE), 40 parts of the epoxy group-modified calcium carbonate from step (3), 10 parts of the amino polysiloxane-modified polyolefin elastomer from step (2), and 4 parts of blowing agent azodicarbonamide were weighed and mixed, and then added to a mixer. The processing temperature range was set to 130 - 150 °C and mixed evenly, and then extruded into a mold and hot-pressed and foamed at 200 - 210 °C to obtain a high-strength calcium plastic sheet.

[0038] The mechanical property test (test thickness 2.5 mm) results of the high-strength calcium plastic sheet obtained in this example are shown in Table 1 below.

[0039] Table 1

[0040]

[0041] It can be seen from the results in Table 1 that the calcium plastic sheet obtained by the present invention has high strength and toughness.

[0042] Example 2

[0043] A preparation method of a high-strength calcium plastic sheet, comprising the following preparation steps:

[0044] (1) N-β-(Aminoethyl)-γ-aminopropylmethyldimethoxysilane (KH-602), octamethylcyclotetrasiloxane (D4), tetramethyldisiloxane (HMM) and tetramethylammonium hydroxide catalyst were added to a reaction flask in a mass ratio of 40:60:12:0.05, stirred and mixed evenly. Nitrogen was introduced into the reaction flask for replacement protection, and the mixture was heated to 90 °C with an electric heating mantle and stirred for a polymerization reaction for 4 h. Then, the temperature was raised to 140 °C to decompose and remove the catalyst and unreacted raw materials under reduced pressure, obtaining a hydrogen-terminated amino polysiloxane. The hydrogen content of the obtained product was detected to be 0.16%, the amino content was 3.20%, the theoretical molecular weight was 1250, and the yield was 83%.

[0045] (2) The hydrogen-terminated amino polysiloxane from step (1) and 1,7-octadiene were added to a reaction flask containing isopropanol solvent in a molar ratio of 1:1.8, mixed and dissolved. Nitrogen was introduced into the reaction flask for replacement protection, and then 0.01% chloroplatinic acid isopropanol solution catalyst was added. The mixture was heated to 90 °C with an electric heating mantle and stirred for a polymerization reaction for 4 h. After detecting that the active hydrogen reaction of the product was complete, the reaction solution was fed into a drying granulator for drying and granulation, obtaining an amino polysiloxane-modified polyolefin elastomer.

[0046] (3) Light calcium carbonate was surface-modified by dry method with 6% epoxy group silane coupling agent KH-560 to obtain epoxy group-modified calcium carbonate.

[0047] (4) By weight, 100 parts of low-density polyethylene (LDPE), 20 parts of the epoxy group-modified calcium carbonate from step (3), 5 parts of the amino polysiloxane-modified polyolefin elastomer from step (2), and 4 parts of blowing agent azodicarbonamide were mixed and then added to a mixer. The processing temperature range was set at 130 - 150 °C and mixed evenly, and then extruded into a mold and hot-pressed and foamed at 200 - 210 °C to obtain a high-strength calcium plastic sheet.

[0048] The mechanical property test (test thickness 2.5 mm) results of the high-strength calcium plastic sheet obtained in this example are shown in Table 2 below.

[0049] Table 2

[0050]

[0051] It can be seen from the results in Table 2 that the calcium plastic sheet obtained by the present invention has high strength and toughness.

[0052] Example 3

[0053] A preparation method of a high-strength calcium plastic sheet, comprising the following preparation steps:

[0054] (1) γ-aminopropylmethyldiethoxysilane (KBE-902), octamethylcyclotetrasiloxane (D4), tetramethyldisiloxane (HMM) and tetramethylammonium hydroxide catalyst were added to a reaction flask in a mass ratio of 20:80:5:0.05, stirred and mixed evenly. Nitrogen was introduced into the reaction flask for replacement and protection, and the mixture was heated to 90 °C with an electric heating mantle and stirred for polymerization reaction for 4 h. Then, the temperature was raised to 140 °C and the pressure was reduced to decompose and remove the catalyst and unreacted raw materials, obtaining a hydrogen-terminated amino polysiloxane. The hydrogen content of the obtained product was detected to be 0.07%, the amino content was 1.72%, the theoretical molecular weight was 2857, and the yield was 90%.

[0055] (2) The hydrogen-terminated amino polysiloxane from step (1) and 1,11-dodecadiene were added to a reaction flask containing isopropanol solvent in a molar ratio of 1:1.1, mixed and dissolved. Nitrogen was introduced into the reaction flask for replacement and protection, and then 0.01% chloroplatinic acid isopropanol solution catalyst was added. The mixture was heated to 90 °C with an electric heating mantle and stirred for polymerization reaction for 4 h. After detecting that the active hydrogen reaction of the product was complete, the reaction solution was input into a drying granulator for drying and granulation, obtaining an amino polysiloxane-modified polyolefin elastomer.

[0056] (3) Light calcium carbonate was surface-modified by dry method with 4% epoxy group silane coupling agent KH-560 to obtain epoxy group-modified calcium carbonate.

[0057] (4) By weighing 100 parts of low-density polyethylene (LDPE), 60 parts of the epoxy group-modified calcium carbonate from step (3), 20 parts of the amino polysiloxane-modified polyolefin elastomer from step (2), and 5 parts of blowing agent azodicarbonamide, they were mixed and then added to a mixer. The processing temperature range was set at 130 - 150 °C and mixed evenly, and then extruded into a mold and hot-pressed and foamed at 200 - 210 °C to obtain a high-strength calcium plastic sheet.

[0058] The mechanical property test (test thickness 2.5 mm) results of the high-strength calcium plastic sheet obtained in this example are shown in Table 3 below.

[0059] Table 3

[0060]

[0061]

[0062] It can be seen from the results in Table 3 that the calcium plastic sheet obtained by the present invention has relatively high strength and toughness.

[0063] Comparative Example 1

[0064] A preparation method of a high-strength calcium plastic sheet, compared with Example 1, without adding an amino polysiloxane-modified polyolefin elastomer, includes the following preparation steps:

[0065] Weigh 100 parts of low-density polyethylene (LDPE), 40 parts of epoxy group-modified calcium carbonate (the same as in Example 1), and 4 parts of blowing agent azodicarbonamide. After mixing, add them to a kneader. Set the processing temperature range to 130 - 150 °C and knead evenly. Then extrude into a mold and hot-press and foam at 200 - 210 °C to obtain a high-strength calcium plastic sheet.

[0066] The test results of the mechanical properties of the high-strength calcium plastic sheet obtained in this comparative example (test thickness 2.5 mm) are shown in Table 4 below.

[0067] Table 4

[0068]

[0069] It can be seen from the comparison results with Example 1 that by adding amino polysiloxane-modified polyolefin elastomer to modify the polyolefin material, the strength and toughness of the obtained calcium plastic sheet can be significantly enhanced.

[0070] Comparative Example 2

[0071] A preparation method of a high-strength calcium plastic sheet includes the following preparation steps:

[0072] (1) Add octamethylcyclotetrasiloxane (D4), tetramethyldisiloxane (HMM), and tetramethylammonium hydroxide catalyst to a reaction flask in a mass ratio of 100:7:0.05, stir and mix evenly. Introduce nitrogen into the reaction flask for replacement protection, heat with an electric heating mantle to 90 °C, stir and carry out a polymerization reaction for 4 h, then raise the temperature to 140 °C and decompress to remove the catalyst and unreacted raw materials to obtain hydrogen-terminated methyl polysiloxane. The hydrogen content of the obtained product is detected to be 0.11%, the theoretical molecular weight is 1818, and the yield is 89%.

[0073] The preparation processes of steps (2) - (4) are the same as those in Example 1.

[0074] The test results of the mechanical properties of the high-strength calcium plastic sheet obtained in this comparative example (test thickness 2.5 mm) are shown in Table 5 below.

[0075] Table 5

[0076]

[0077] It can be seen from the comparison results with Example 1 and Comparative Example 1 that by using a polyolefin elastomer modified with polysiloxane without amino to modify the polyolefin material, the toughness of the obtained calcium plastic sheet can be significantly improved, but the improvement effect on strength is not significant.

[0078] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A high-strength calcium plastic sheet, characterized in that, It comprises the following raw material components by weight parts: 80 - 100 parts of polyolefin, 20 - 60 parts of epoxy group modified calcium carbonate, 5 - 20 parts of amino polysiloxane modified polyolefin elastomer, 1 - 8 parts of foaming agent; The amino polysiloxane modified polyolefin elastomer is prepared by the following method: (1) Heat and polymerize amino silane monomer, methyl silane monomer and hydrogen silane end-capping agent under the condition of catalyst to obtain hydrogen end-capped amino polysiloxane; (2) Dissolve hydrogen end-capped amino polysiloxane and α,ω-diene in an organic solvent, then add a hydrosilylation catalyst and carry out heating copolymerization reaction. After the reaction is completed, dry and granulate to obtain amino polysiloxane modified polyolefin elastomer; In step (1), the addition amounts of the amino silane monomer, methyl silane monomer and hydrogen silane end-capping agent are controlled so that the weight-average molecular weight of the obtained hydrogen end-capped amino polysiloxane is 500 - 3000, and the mass percentage content of amino group is 0.5% - 5%; In step (2), the α,ω-diene is selected from at least one of 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,10-undecadiene, 1,11-dodecadiene; the molar ratio of the hydrogen end-capped amino polysiloxane to the α,ω-diene in the reaction is 1:1.1 - 1.8; In step (1), the amino silane monomer is selected from one or more of γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane; In step (1), the methyl silane monomer is selected from one or more of octamethylcyclotetrasiloxane, dimethyldimethoxysilane, dimethyldiethoxysilane; the hydrogen silane end-capping agent is selected from one or more of tetramethyldisiloxane, dimethylmethoxyhydrogensilane, dimethylethoxyhydrogensilane.

2. The high-strength calcium plastic sheet according to claim 1, characterized in that, The polyolefin is selected from polyethylene or polypropylene; the epoxy group modified calcium carbonate is the epoxy group modified calcium carbonate surface-modified with epoxy group silane coupling agent KH-560 or KH-561; the foaming agent is selected from one or more of azodicarbonamide, N,N-dinitrosopentamethylenetetramine, sodium bicarbonate, ammonium bicarbonate.

3. A high-strength calcium plastic sheet according to claim 1, characterized in that, In step (1), the catalyst is selected from at least one of sodium hydroxide, potassium hydroxide, sodium silanolate, potassium silanolate, tetramethylammonium hydroxide; the temperature of the heating polymerization reaction is 80 - 140 °C, and the time is 2 - 8 h.

4. A high-strength calcium plastic sheet according to claim 1, characterized in that, In step (2), the organic solvent is selected from one or more of isopropanol, ethyl acetate, cyclohexane, petroleum ether; the hydrosilylation catalyst is chloroplatinic acid isopropanol solution; the temperature of the heating copolymerization reaction is 80 - 100 °C, and the time is 2 - 8 h.

5. A method for preparing a high-strength calcium plastic sheet according to any one of claims 1 to 4, characterized in that, It comprises the following preparation steps: Mix the amino polysiloxane modified polyolefin elastomer, epoxy group modified calcium carbonate, polyolefin material and foaming agent, then add them to a mixer and mix evenly, and then extrude them into a mold for hot pressing and foaming to form a high-strength calcium plastic board.

6. Application of the high-strength calcium plastic board according to any one of claims 1 - 4 in the preparation of packing boxes.

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