Coarse-hole reticular polyurethane sponge as well as preparation method and application thereof

Abstract

The invention relates to coarse mesh polyurethane sponge as well as a preparation method and application thereof. The sponge is prepared from the following raw materials in parts by weight: 80 to 90 parts of composite polyester polyol, 10 to 20 parts of polyether polyol, 50 to 60 parts of isocyanate, 3 to 4 parts of water, 1.4 to 1.7 parts of silicone oil, 1 to 1.3 parts of catalyst and 1 to 2 parts of pore opening agent. Compared with the prior art, the composite polyester polyol and the polyether polyol have a synergistic effect, and have remarkable benign influence on the opening degree, the opening stability and the strength of the polyurethane sponge, so that the polyurethane foam can still keep excellent physical properties and long-term stability while keeping the high opening degree of PPI (Polypropylene Index) of 5-15.

Description

Technical Field

[0001] The invention relates to the technical field of reticulated polyurethane, and in particular to a coarse-pore reticulated polyurethane sponge and a preparation method and application thereof. Background Art

[0002] The pore size of polyester sponges produced by existing technologies is generally small, which limits their use in application scenarios that require large-pore filter media. In particular, in the field of ceramic filter sheets, different types of filter media and different filter flow rate requirements result in different mesh gap requirements for filter sheets, which correspond to different PPI (pores per inch of sponge) values ​​on polyester sponges. However, it is difficult to produce polyurethane sponges with a PPI value of less than 15 with existing technologies, that is, it is difficult to produce polyurethane sponges with large pores.

[0003] This is because polyester sponge foaming is more difficult than polyether sponge products. This is mainly because polyester sponge is prone to collapse and shrinkage during the foaming process, which makes it impossible to form a stable macroporous structure. In addition, the foaming raw materials themselves contain some small bubbles. These bubbles not only affect the thoroughness and quality of the pore nucleation reaction, but also because the gas solubility of different raw materials is different, the presence of bubbles also affects the accuracy of the raw material ratio.

[0004] In summary, polyester sponges (especially polyurethane sponges) currently have certain shortcomings and challenges in terms of pore size, preparation process, and raw material processing. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a coarse-pored mesh polyurethane sponge and a preparation method and application thereof. Specific polyester polyols and polyether polyols are selected for compounding, while having the advantages of the pore stability of the polyether sponge and the high toughness and uniform voids of the polyester sponge, to obtain a polyurethane sponge with a PPI of 5-15.

[0006] To achieve the above object, the technical solution adopted by the present invention is: In a first aspect, the present invention provides a coarse-pored mesh polyurethane sponge, comprising the following raw materials in parts by weight: 80-90 parts of composite polyester polyol, 10-20 parts of polyether polyol, 50-60 parts of isocyanate, 3-4 parts of water, 1.4-1.7 parts of silicone oil, 1-1.3 parts of catalyst and 1-2 parts of pore opening agent; Wherein, the composite polyester polyol is a composition of phthalic anhydride modified polyester polyol, soft foam polyester polyol and poly-ε-caprolactone polyol in a mass ratio of (0.2-0.5): 1:1, the manufacturer of phthalic anhydride modified polyester polyol is Asahikawa Chemical (Suzhou) Co., Ltd., the model is XCPA-2000DE, and the hydroxyl value is 53-59 mgKOH / g; the manufacturer of soft foam polyester polyol is Shandong Chongmei New Material Technology Co., Ltd., the model is CM-580, the hydroxyl value is 56-62 mgKOH / g, and the viscosity at 25°C is 21500mpa.s; the manufacturer of poly-ε-caprolactone polyol is Daicel Chemical Industry Co., Ltd., the model is PCL220NP1, the hydroxyl value is 56-62 mgKOH / g, and the number average molecular weight is 2000; The polyether polyol is a primary hydroxyl-terminated polyether polyol composed of propylene oxide and ethylene oxide, produced by Jiahua Chemical (Shanghai) Co., Ltd., model Puranol P156, and number average molecular weight of 5,000.

[0007] Specifically, the polyether polyol of the present invention is a primary hydroxyl-terminated polyether polyol composed of propylene oxide and ethylene oxide, which plays a role in opening holes in the sponge foaming process. This is because the three-membered ring structure of PO and EO has high reactivity, and they can form more active sites in the ring-opening polymerization process, thereby forming more open-cell structures in the polyurethane sponge foaming process. In particular, the addition of EO can significantly improve the hydrophilicity and fluidity of the polyether polyol, further promote the formation of open holes, and the polyurethane sponge with high open porosity may have more open pores, which may affect the pore size and distribution described by the PPI value of the sponge.

[0008] Phthalic anhydride modified polyester polyol belongs to hard foam polyester polyol. Since the polyester polyol modified by phthalic anhydride has a high crosslinking density and mechanical strength, it can form a more stable network structure during the sponge foaming process, thereby improving the carrying capacity of the polyurethane sponge, preventing the merging and closed-cell phenomena of the holes, thereby improving the openness and preventing shrinkage. Poly-ε-caprolactone polyol can maintain the pore structure of the polyurethane sponge because of its high molecular weight and good mechanical properties, prevent the merging and closed-cell phenomena of the holes, thereby avoiding the strength reduction caused by the large pore size. The viscosity of the soft foam polyester polyol used in the present invention is 21500mpa·s at 25°C. The flow of this high viscosity liquid between bubbles is restricted, so that the bubble wall can maintain a certain thickness and strength and is not easy to break, which helps the bubble to maintain its integrity during the growth process, promotes the formation of a coarse pore structure, and it also helps to form a more open pore structure, reducing the number of closed cells, and the open pore structure makes it easier for the gas to circulate inside the foam, which is conducive to the formation of larger pores, thereby reducing the PPI value of the effective polyurethane sponge.

[0009] In summary, polyether polyols mainly promote the increase of open cell degree, while composite polyester polyols further improve the stability, load-bearing capacity and strength of the open cells. This combination enables polyurethane foam to maintain excellent physical properties and long-term stability while maintaining high open cell degree.

[0010] Preferably, the catalyst is an amine catalyst and / or an organotin catalyst.

[0011] Preferably, the amine catalyst is one of triethylenediamine, triethanolamine, triethylamine or N-ethylmorpholine; and / or, the tin catalyst is stannous octoate and / or dibutyltin dilaurate.

[0012] Preferably, the silicone oil is produced by Evonik Degussa and its model is B8002.

[0013] Preferably, the isocyanate is diphenylmethane diisocyanate, and the Index value is 120.

[0014] Preferably, the manufacturer of the cell opener is Jiangsu Bader Polyurethane Co., Ltd., and the model is MK01.

[0015] In a second aspect, the present invention provides a method for preparing the coarse-pored mesh polyurethane sponge, comprising the following steps: S1. Add the formulated amount of composite polyester polyol, polyether polyol, silicone oil and catalyst into a mixer, stir and mix them evenly at 35-50° C. to obtain a mixed material A; S2, stirring and mixing the formulated amount of isocyanate, pore opening agent and water at 35-50° C. to obtain a mixture B; S3: Mixing the mixed material A and the mixed material B and transferring them to a mold, and performing mixing and foaming polymerization at room temperature to obtain a polyurethane soft foam; S4, reticulating the polyurethane soft foam to obtain the coarse-pore reticulated polyurethane sponge.

[0016] Preferably, in step S3, the temperature of the foaming polymerization is 18-25°C and the time is 12-24 hours. Preferably, the reticulation treatment is an explosion treatment.

[0017] Specifically, the reticulation treatment is an explosion treatment, and the specific steps are: putting the polyurethane soft foam into a treatment reactor, first evacuating the reactor, then injecting explosive gas of a certain pressure, and igniting and detonating the gas after diffusion for a period of time to obtain the reticulated polyurethane soft foam.

[0018] In a third aspect, the present invention provides use of the coarse-porous mesh polyurethane sponge in the first aspect in preparing a ceramic filter sheet.

[0019] Compared with the prior art, the present invention has the following beneficial effects: (1) The polyether polyol in the present invention can increase the porosity of the polyurethane sponge, and the phthalic anhydride-modified polyester polyol and the poly-ε-caprolactone polyol can significantly increase the strength of the polyurethane sponge foam, avoiding the reduction in strength due to large pore size. The high-viscosity soft foam polyol at room temperature (25°C) helps to form larger pores, thereby reducing the PPI value of the effective polyurethane sponge. The polyether polyol in the present invention has a synergistic effect with the phthalic anhydride-modified polyester polyol, the soft foam polyester polyol and the poly-ε-caprolactone polyol, and has a significant positive effect on the porosity, porosity stability and strength of the polyurethane, so that the polyurethane foam can maintain a high porosity of 5-15 while still maintaining excellent physical properties and long-term stability.

[0020] (2) The polyurethane sponge of the present invention has the advantages of both the pore stability of polyether sponge and the high toughness and uniform pores of polyester sponge, and can be used as a skeleton of ceramic filter sheets. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a physical picture of the polyurethane sponge of Example 1. DETAILED DESCRIPTION

[0022] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0023] The sources of materials used in the following examples and comparative examples are as follows: Primary hydroxyl-terminated polyether polyol composed of propylene oxide and ethylene oxide: the manufacturer is Jiahua Chemical (Shanghai) Co., Ltd., the model is Puranol P156, and the number average molecular weight is 5000; Polyether polyol: manufacturer is Jiahua Chemical (Shanghai) Co., Ltd., model is Puranol LV5000, number average molecular weight is 5000; Phthalic anhydride modified polyester polyol: manufacturer is Asahikawa Chemical (Suzhou) Co., Ltd., model is XCPA-2000DE, hydroxyl value is 53-59 mgKOH / g; Soft foam polyester polyol: manufacturer is Shandong Chongmei New Material Technology Co., Ltd., model is CM-580, hydroxyl value is 56-62 mgKOH / g, viscosity is 21500mpa·s at 25℃; Poly-ε-caprolactone polyol: manufacturer is Japan Daicel Chemical Industry Co., Ltd., model number is PCL220NP1, hydroxyl value is 56-62 mgKOH / g, number average molecular weight is 2000; Diphenylmethane diisocyanate: manufacturer is Shanghai Yien Chemical Technology Co., Ltd., model number is R024901; Cell opener: The manufacturer is Jiangsu Bader Polyurethane Co., Ltd., model MK01; Silicone oil: polysiloxane-polyalkylene oxide-block copolymer, manufacturer: Evonik Degussa, model: B8002; Triethylenediamine: The manufacturer is Evonik Industries of Germany, model number is DABCO33LV; Dibutyltin dilaurate: The manufacturer is American Momentive Advanced Materials Company, model number is D22; Unless otherwise specified, other materials, reagents, etc. used in the examples and comparative examples can be obtained from commercial sources.

[0024] Example 1

[0025] A coarse-pored mesh polyurethane sponge comprises the following raw materials in parts by weight: 85 parts of a composite polyester polyol, 15 parts of a polyether polyol, 55 parts of an isocyanate, 3 parts of water, 1.5 parts of a silicone oil, 1.2 parts of a catalyst and 1.5 parts of a pore-opening agent; wherein the composite polyester polyol is a composition of phthalic anhydride-modified polyester polyol, a soft-foam polyester polyol and a poly-ε-caprolactone polyol in a mass ratio of 0.4:1:1, the polyether polyol is a primary hydroxyl-terminated polyether polyol composed of propylene oxide and ethylene oxide, the isocyanate is diphenylmethane diisocyanate with an Index value of 120, and the catalyst is triethylenediamine.

[0026] The method for preparing a coarse-pored mesh polyurethane sponge comprises the following steps: S1. Add the formulated amount of composite polyester polyol, polyether polyol, silicone oil and catalyst into a mixer, and stir and mix them evenly at 40° C. to obtain a mixed material A; S2, stirring and mixing the isocyanate, the pore opening agent and the water in the formula at 40° C. to obtain a mixture B; S3: Mixing the mixed material A and the mixed material B and transferring them to a mold, and performing mixed foaming polymerization at room temperature for 18 hours to obtain a polyurethane soft foam; S4. Put the polyurethane soft foam into a processing reactor, first evacuate it, then inject an explosive gas of a certain pressure, diffuse it for 6 hours, and then ignite and detonate it to obtain a reticulated polyurethane soft foam, wherein the explosive gas is a mixture of CH4 and O2 with a pressure ratio of 4.5:1, and the pressure of the explosive gas is 14MPa.

[0027] Example 2

[0028] A coarse-pored mesh polyurethane sponge comprises the following raw materials in parts by weight: 80 parts of a composite polyester polyol, 10 parts of a polyether polyol, 50 parts of an isocyanate, 3 parts of water, 1.4 parts of silicone oil, 1 part of a catalyst and 1 part of a pore-opening agent; wherein the composite polyester polyol is a composition of phthalic anhydride-modified polyester polyol, a soft-foam polyester polyol and a poly-ε-caprolactone polyol in a mass ratio of 0.2:1:1, the polyether polyol is a primary hydroxyl-terminated polyether polyol composed of propylene oxide and ethylene oxide, the isocyanate is diphenylmethane diisocyanate with an Index value of 120, and the catalyst is dibutyltin dilaurate.

[0029] The method for preparing a coarse-pored mesh polyurethane sponge is characterized by comprising the following steps: S1. Add the formulated amount of composite polyester polyol, polyether polyol, silicone oil and catalyst into a mixer, and stir and mix them evenly at 35° C. to obtain a mixed material A; S2, stirring and mixing the isocyanate, the pore opening agent and the water in the formula at 35° C. to obtain a mixture B; S3: Mixing the mixed material A and the mixed material B and transferring them to a mold, and performing mixed foaming polymerization at room temperature for 24 hours to obtain a polyurethane soft foam; S4. Put the polyurethane soft foam into a treatment reactor, first evacuate it, then inject an explosive gas of a certain pressure, diffuse it for 8 hours and then ignite and detonate it to obtain a reticulated polyurethane soft foam, wherein the explosive gas is a mixture of CH4 and O2 with a pressure ratio of 4:1, and the pressure of the explosive gas is 10MPa.

[0030] Example 3

[0031] A coarse-pore mesh polyurethane sponge, characterized in that it comprises the following raw materials in parts by weight: 90 parts of composite polyester polyol, 20 parts of polyether polyol, 60 parts of isocyanate, 4 parts of water, 1.7 parts of silicone oil, 1.3 parts of catalyst and 2 parts of pore opener; wherein the composite polyester polyol is a composition of phthalic anhydride-modified polyester polyol, soft foam polyester polyol and poly-ε-caprolactone polyol in a mass ratio of 0.5:1:1, the polyether polyol is a primary hydroxyl-terminated polyether polyol composed of propylene oxide and ethylene oxide, the isocyanate is diphenylmethane diisocyanate with an Index value of 120, and the catalyst is triethylenediamine.

[0032] The method for preparing a coarse-pored mesh polyurethane sponge is characterized by comprising the following steps: S1. Add the formulated amount of composite polyester polyol, polyether polyol, silicone oil and catalyst into a mixer, and stir and mix them evenly at 50° C. to obtain a mixed material A; S2, stirring and mixing the isocyanate, the pore opening agent and the water in the formula at 50° C. to obtain a mixture B; S3: Mixing the mixed material A and the mixed material B and transferring them to a mold, and performing mixing and foaming polymerization at room temperature for 12 hours to obtain a polyurethane soft foam; S4. Put the polyurethane soft foam into a treatment reactor, first evacuate it, then inject an explosive gas of a certain pressure, diffuse it for 3 hours and then ignite and detonate it to obtain a reticulated polyurethane soft foam, wherein the explosive gas is a mixture of CH4 and O2 with a pressure ratio of 4.25:1, and the pressure of the explosive gas is 15MPa.

[0033] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that no polyether polyol is added, and an equal amount of composite polyester polyol is used to make up for the missing amount.

[0034] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the primary hydroxyl-terminated polyether polyol composed of propylene oxide and ethylene oxide is replaced by polyether polyol Puranol LV5000.

[0035] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the total amount of composite polyester polyol remains unchanged, phthalic anhydride-modified polyester polyol is not added, and the missing amount is made up by using soft foam polyester polyol and poly-ε-caprolactone polyol in a mass ratio of 1:1.

[0036] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that the total amount of composite polyester polyol remains unchanged, soft foam polyester polyol is not added, and phthalic anhydride modified polyester polyol and poly-ε-caprolactone polyol with a mass ratio of 0.4:1 are used to make up for the missing amount.

[0037] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that the total amount of composite polyester polyol remains unchanged, poly-ε-caprolactone polyol is not added, and phthalic anhydride-modified polyester polyol and soft foam polyester polyol with a mass ratio of 0.4:1 are used to make up for the missing amount.

[0038] Comparative Example 6 The difference between Comparative Example 6 and Example 1 is that the total amount of the composite polyester polyol remains unchanged, and the composite polyester polyol is a composition of phthalic anhydride-modified polyester polyol, soft foam polyester polyol and poly-ε-caprolactone polyol in a mass ratio of 1:0.4:1.

[0039] Comparative Example 7 The difference between Comparative Example 7 and Example 1 is that the total amount of the composite polyester polyol remains unchanged, and the composite polyester polyol is a composition of phthalic anhydride-modified polyester polyol, soft foam polyester polyol and poly-ε-caprolactone polyol in a mass ratio of 1:1:0.4.

[0040] Performance Testing (1) Density, cell void size and porosity Testing method: The sponge materials of Examples 1-3 and Comparative Examples 1-7 were tested for density, reticular pore size and open porosity respectively: the foam density was measured according to GB / T 6343-2009, the open porosity was measured according to GB / T 10799-2008, and the reticular pore size (PPI value) was usually expressed by the number of cells per unit linear length (25 mm). The specific data are shown in Table 1.

[0041] (2) Mechanical properties test Testing method: The sponge materials of Examples 1-3 and Comparative Examples 1-7 were tested for tensile strength and elongation at break according to ISO1798, their tear strength according to ISO8067, and their 40% compressive strength according to ISO3386. The specific data are shown in Table 1.

[0042] Table 1 Performance data of each group of polyurethane sponge Group / Performance <![CDATA[Density / kg·m -3 > Pore ​​size (number / 25mm) Opening rate / % Tensile strength / KPa Elongation at break / % <![CDATA[Tear strength / N·mm -1 > 40% compression strength / KPa Example 1 73.2 5 99.72 229 256 1.40 6.16 Example 2 74.5 15 99.51 223 253 1.37 6.04 Example 3 73.4 9 99.62 225 250 1.32 6.11 Comparative Example 1 52.5 36 79.54 182 213 0.64 4.72 Comparative Example 2 49.4 29 84.58 202 233 0.97 5.67 Comparative Example 3 45.6 23 81.64 198 230 0.90 5.29 Comparative Example 4 46.7 24 81.40 195 227 0.86 5.27 Comparative Example 5 47.4 20 80.77 191 223 0.84 5.20 Comparative Example 6 63.0 19 86.87 202 236 1.16 5.76 Comparative Example 7 64.0 20 86.92 209 237 1.13 5.80 It can be seen from Table 1 that, in combination with the data of Example 1 and Comparative Examples 1-2, in the preparation of the polyurethane sponge of the present invention, the selective addition of primary hydroxyl-terminated polyether polyols composed of propylene oxide and ethylene oxide can increase the pore size of the polyurethane sponge, reduce the PPI value of the sponge, and improve the mechanical properties of the polyurethane sponge.

[0043] Combining the data of Example 1 and Comparative Application Examples 3-5, it can be seen that the component composition of the composite polyester polyol has a great influence on the PPI value, porosity and strength of the polyurethane. When phthalic anhydride-modified polyester polyol, soft foam polyester polyol and poly-ε-caprolactone polyol are used in combination, the PPI value of the polyurethane sponge is lower, and the open-pore stability and strength are better. When any one of phthalic anhydride-modified polyester polyol, soft foam polyester polyol and poly-ε-caprolactone polyol is missing, the performance of the polyurethane sponge decreases.

[0044] Combining the data of Example 1 and Comparative Examples 6-7, it can be seen that when the mass ratio of phthalic anhydride modified polyester polyol, soft foam polyester polyol and poly-ε-caprolactone polyol is (0.2-0.5):1:1, the performance of the polyurethane sponge reaches a better level.

[0045] In summary, the present invention adds a specific type of polyether polyol and a specific composition of composite polyester polyol, so that the polyurethane foam can maintain a high open cell degree of PPI of 5-15 while still maintaining excellent physical properties and long-term stability.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A coarse-pored mesh polyurethane sponge, characterized in that: The method comprises the following raw materials in parts by weight: 80-90 parts of composite polyester polyol, 10-20 parts of polyether polyol, 50-60 parts of isocyanate, 3-4 parts of water, 1.4-1.7 parts of silicone oil, 1-1.3 parts of catalyst and 1-2 parts of pore opening agent; Wherein, the composite polyester polyol is a composition of phthalic anhydride modified polyester polyol, soft foam polyester polyol and poly-ε-caprolactone polyol in a mass ratio of (0.2-0.5): 1:1, the manufacturer of phthalic anhydride modified polyester polyol is Asahikawa Chemical (Suzhou) Co., Ltd., the model is XCPA-2000DE, and the hydroxyl value is 53-59 mgKOH / g; the manufacturer of soft foam polyester polyol is Shandong Chongmei New Material Technology Co., Ltd., the model is CM-580, the hydroxyl value is 56-62 mgKOH / g, and the viscosity at 25°C is 21500 mpa·s; the manufacturer of poly-ε-caprolactone polyol is Daicel Chemical Industries, Ltd., the model is PCL220NP1, the hydroxyl value is 56-62 mgKOH / g, and the number average molecular weight is 2000; The polyether polyol is a primary hydroxyl-terminated polyether polyol composed of propylene oxide and ethylene oxide, produced by Jiahua Chemical (Shanghai) Co., Ltd., model number Puranol P156, and number average molecular weight of 5,000.

2. The coarse-pored mesh polyurethane sponge according to claim 1, characterized in that: The catalyst is an amine catalyst and / or an organotin catalyst.

3. The coarse-pored mesh polyurethane sponge according to claim 2, characterized in that: The amine catalyst is one of triethylenediamine, triethanolamine, triethylamine or N-ethylmorpholine; and / or the tin catalyst is stannous octoate and / or dibutyltin dilaurate.

4. The coarse-pored mesh polyurethane sponge according to claim 1, characterized in that: The silicone oil is produced by Evonik Degussa and its model is B8002.

5. The coarse-pored mesh polyurethane sponge according to claim 1, characterized in that: The isocyanate is diphenylmethane diisocyanate, and the Index value is 120.

6. The coarse-pored mesh polyurethane sponge according to claim 1, characterized in that: The manufacturer of the cell opener is Jiangsu Bader Polyurethane Co., Ltd., and the model is MK01.

7. The method for preparing the coarse-pored mesh polyurethane sponge according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Add the formulated amount of composite polyester polyol, polyether polyol, silicone oil and catalyst into a mixer, and stir and mix them evenly at 35-50° C. to obtain a mixed material A; S2, stirring and mixing the formulated amount of isocyanate, pore opening agent and water at 35-50° C. to obtain a mixture B; S3: Mixing the mixed material A and the mixed material B and transferring them to a mold, and performing mixing and foaming polymerization at room temperature to obtain a polyurethane soft foam; S4, reticulating the polyurethane soft foam to obtain the coarse-pore reticulated polyurethane sponge.

8. The method for preparing the coarse-pored mesh polyurethane sponge according to claim 7, characterized in that: In step S3, the temperature of the foaming polymerization is 18-25° C. and the time is 12-24 hours.

9. The method for preparing the coarse-pored mesh polyurethane sponge according to claim 7, characterized in that: The netting treatment is an explosion treatment.

10. Use of the coarse-pored mesh polyurethane sponge according to any one of claims 1 to 6 in preparing a ceramic filter sheet.

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