Compression-resistant polyurethane foam and preparation method thereof

Abstract

The invention relates to the technical field of foam materials, in particular to compression-resistant polyurethane foam which comprises a component A and a component B, wherein the component A is prepared from at least one of isocyanate or modified isocyanate; wherein the component B comprises polyether polyol, a chain extender, deionized water, a catalyst and a surface tension regulator; wherein based on the mass of the polyether polyol, the mass of the chain extender accounts for 1-3 wt% of the total mass of the polyether polyol; the mass of the deionized water accounts for 0.5 wt%-1.5 wt% of the total mass of the polyether polyol; the mass of the catalyst accounts for 1wt%-2wt% of the total mass of the polyether polyol; the mass of the surface tension regulator accounts for 0.5 wt%-2wt% of the total mass of the polyether polyol. Two-component liquid raw materials convenient to mix and process are adopted, spraying of a point-shaped structure and coating of a planar structure are creatively combined, and the material is endowed with supernormal and excellent compression resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of foaming materials, in particular to a compression-resistant polyurethane foam and a preparation method thereof. Background Art

[0002] Polyurethane foam is a common material with a wide range of applications. The latest domestic technologies for producing thin-film polyurethane microporous foam utilize a coating molding process to produce continuous rolls. Due to its exceptional sealing and shock-absorbing properties, it is widely used in handheld electronic devices, home electronics, and commercial electronic devices.

[0003] Polyurethane foam materials are generally single-component or two-component products, widely used across various industries. They are generally categorized into molding and coating methods. Single-component foams, meaning a single component, involve mixing all the necessary raw materials for foaming in a container at once. The mixture is then poured or coated onto a substrate, where it cures to form the desired product. The curing principle is generally moisture curing, where the product reacts with moisture in the air to achieve a balanced ratio, resulting in a solid product.

[0004] Two-component foaming involves separating the raw materials into two separate components, one of which is a hydroxyl component, typically a mixture of a polyol, catalyst, chain extender, and water, or a mixture of a polyol, chain extender prepolymer, water, and catalyst. The other is an isocyanate component, typically an isocyanate or a modified isocyanate prepolymer. Water, acting as the gas source during the foaming process, reacts chemically with the isocyanate to release CO2. The preparation process utilizes a method of metering and quantitative delivery, with the two raw materials delivered to the mixing unit at regular intervals and in fixed quantities. After mixing, the raw materials enter a preparatory mold or coating mechanism for molding. Ultimately, the chemical reaction between the two components results in a solid product.

[0005] Whether one-component or two-component polyurethane products, the raw materials are either liquid or liquid after high-temperature heating to ensure fluidity and workability before molding. They are foamed in a closed mold or on a base film. From a microscopic perspective, the base raw materials for both are identical, with no significant differences, resulting in similar physical properties. Summary of the Invention

[0006] The purpose of the present invention is to provide a compression-resistant polyurethane foam and a preparation method thereof in view of the deficiencies in the prior art.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] The present invention provides a compression-resistant polyurethane foam, comprising a component A and a component B;

[0009] Wherein, component A comprises: at least one of isocyanate or modified isocyanate;

[0010] Wherein, component B comprises: polyether polyol, chain extender, deionized water, catalyst and surface tension regulator;

[0011] Among them, the quality of polyether polyol is taken as the benchmark.

[0012] The mass of the chain extender accounts for 1wt%-3wt% of the total mass of the polyether polyol;

[0013] The mass of deionized water accounts for 0.5wt%-1.5wt% of the total mass of the polyether polyol;

[0014] The mass of the catalyst accounts for 1wt%-2wt% of the total mass of the polyether polyol;

[0015] The mass of the surface tension regulator accounts for 0.5wt%-2wt% of the total mass of the polyether polyol.

[0016] Furthermore, the isocyanate is at least one of toluene diisocyanate and isophorone diisocyanate, and the modified isocyanate is polymethylene polyphenyl polyisocyanate.

[0017] Furthermore, the molar ratio of toluene diisocyanate to isophorone diisocyanate is 1:1-7:3, and the content of isocyanate groups in the polymethylene polyphenyl polyisocyanate is 30 wt %-50 wt %.

[0018] Furthermore, the polyether polyol is an ethylene oxide (propylene) type polyether polyol, the chain extender is a diol, the catalyst is at least one of an organic metal catalyst or an amine catalyst, and the surface tension regulator is liquid silicone oil.

[0019] Furthermore, the ethylene oxide (propylene) alkane polyether polyol is a polyethylene oxide-propylene copolymer triol with glycerol as an initiator;

[0020] The diol is ethylene glycol or 1,4-butanediol;

[0021] The organometallic catalyst is bismuth isooctanoate, and the amine catalyst is triethylenediamine;

[0022] Liquid silicone oil is polydimethylsiloxane.

[0023] Furthermore, the molecular weight of the polyethylene oxide-propylene copolyol is 500-6000, and the mass ratio of bismuth isooctanoate to triethylenediamine is 1:1.

[0024] A method for preparing a compression-resistant polyurethane foam as described in any of the preceding items, comprising the steps of:

[0025] Step 1: Mix component A and component B at a mixing speed of 5000 rpm to 6000 rpm to form a mixture;

[0026] Step 2: spraying the mixture in step 1 onto the substrate at a thickness of 3 μm to 10 μm with 100 to 1000 dot structures per square centimeter, and performing a first curing after spraying to obtain a dot coating;

[0027] Step 3: Apply the mixture in step 1 to the surface of the dot coating with a thickness of 10 μm-20 μm, and perform a second curing after the coating is completed to obtain a surface coating;

[0028] Step 4: Repeat steps 2 and 3 in sequence until the dot coating has 7 to 10 layers, the surface coating has 7 to 10 layers, and the total number of layers of the dot coating and the surface coating is 14 to 20 layers, thereby obtaining a polyurethane microporous foam.

[0029] Step 5: subjecting the polyurethane microporous foam to a curing treatment to obtain compression-resistant polyurethane foam.

[0030] Furthermore, the mixing time of component A and component B is 5s-10s, the temperature of the first curing is 90°C-120°C, and the temperature of the second curing is 80°C-110°C.

[0031] Furthermore, in step five, the temperature of the aging treatment is 40° C.-50° C., and the aging treatment time is 12 h-15 h.

[0032] Furthermore, the substrate in step 2 is a polyurethane film or a PET substrate.

[0033] The present invention adopts the above technical solution, which has the following technical effects compared with the prior art:

[0034] In summary, the present invention uses a two-component liquid raw material that is easy to mix and process, and creatively combines the spraying of a dot structure with the coating of a surface structure. That is, on a supporting film, a fixed number of dots are sprayed per unit area to prepare a dot-like coating. The dot-shaped polyurethane foam on the coating is inherently compressible, and there are gaps between the dots, which increases the compressible space. At the same time, a planar structure of a certain thickness is coated on the dot-shaped coating, and after curing, the coating layer forms a continuous and complete plane. The dot-surface structure is interwoven and arranged. When the number of layers reaches a certain number, a three-dimensional "dot-surface-dot-surface" structure is formed. When the surface layer is compressed, the microscopic polyurethane foam pores in the dot-surface act as countless tiny shock-absorbing units to absorb external compression energy. At the same time, the multi-layer dot-surface structure at the macro level can work together with the tiny bubble shock-absorbing units to offset the external compression force to the greatest extent, protecting the bubble wall from breaking due to large stress and repeated compression to the greatest extent, giving the material exceptionally excellent compression resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the spraying sequence of the dot structure and the surface coating of the present invention; DETAILED DESCRIPTION

[0036] The specific embodiments of the present invention will be described in detail below.

[0037] Unless otherwise defined, technical or scientific terms used in the claims and the specification shall have the same general meaning as understood by persons having ordinary skills in the technical field to which the present invention belongs.

[0038] The words "include" or similar used in the patent application specification and claims of the present invention mean that the items before "include" include the items listed after "include" or their equivalents, and do not exclude other items.

[0039] The numerical values ​​mentioned in the present invention include all numerical values ​​that increase by one unit from the lowest to the highest, assuming that there is at least two units between any lower value and the higher value. For example, if a component or a physical quantity is said to be from 1 to 100, preferably from 10 to 90, and most preferably from 20 to 80, it is intended that values ​​such as 5 to 95, 14 to 76, 23 to 67, 32 to 58, and 41 to 49 are clearly listed in this specification; for values ​​less than 1, 0.0001, 0.001, 0.01, or 0.1 are considered to be more appropriate units. The above examples are for illustrative purposes only. In fact, all numerical combinations between the lowest value and the highest value listed are considered to be clearly listed in this specification in a similar manner.

[0040] Example 1

[0041] This embodiment 1 provides a compression-resistant polyurethane foam, comprising: component A and component B; wherein,

[0042] Component A is an isocyanate mixture, specifically composed of toluene diisocyanate (TDI) and isophorone diisocyanate (IPDI): wherein,

[0043] Toluene diisocyanate (TDI): mass 59.89 g;

[0044] Isophorone diisocyanate (IPDI): mass 76.45 g;

[0045] The molar ratio of toluene diisocyanate (TDI) to isophorone diisocyanate (IPDI) is 1:1.

[0046] Component B includes: polyether polyol, chain extender, deionized water, catalyst and surface tension regulator;

[0047] Among them, the quality of polyether polyol is taken as the benchmark.

[0048] The polyether polyol is polyethylene oxide-propylene copolymer triol with glycerol as the initiator, with a molecular weight of 500 and a mass of 200 g;

[0049] The chain extender is ethylene glycol, and the mass of the chain extender accounts for 1wt% of the total mass of the polyether polyol, i.e., 2g;

[0050] The mass of deionized water accounts for 0.5wt% of the total mass of the polyether polyol;

[0051] The catalyst is prepared by mixing 1g of bismuth isooctanoate and 1g of triethylenediamine, the mass of the catalyst accounts for 1wt% of the total mass of the polyether polyol, and the mass ratio of bismuth isooctanoate to triethylenediamine is 1:1;

[0052] The surface tension regulator is polydimethylsiloxane with a molecular weight of 1000, and the mass of the polydimethylsiloxane accounts for 0.5 wt % of the total mass of the polyether polyol, that is, 1 g.

[0053] Example 2

[0054] This embodiment 2 provides a method for preparing a compression-resistant polyurethane foam as in embodiment 1, the steps comprising:

[0055] Step 1: Mix component A and component B at 6000 rpm for 5 seconds to form a mixture;

[0056] Step 2: spray the mixture in step 1 onto a PET substrate at a thickness of 3 μm with 100 dot structures per square centimeter. After spraying, perform a first curing at a temperature of 90° C. to obtain a dot coating.

[0057] Step 3: Apply the mixture in step 1 to the surface of the dot coating with a thickness of 10 μm, and perform a second curing after the coating is completed. The temperature of the second curing is 80° C. to obtain a surface coating;

[0058] Step 4: Repeat steps 2 and 3 in sequence until the dot coating has 8 layers, the surface coating has 8 layers, and the total number of the dot coating and surface coating is 16 layers, thereby obtaining a polyurethane microporous foam.

[0059] Step 5: Curing the polyurethane microporous foam at a temperature of 40° C. for 12 hours to obtain compression-resistant polyurethane foam.

[0060] Example 3

[0061] This embodiment 3 provides a compression-resistant polyurethane foam, comprising: component A and component B; wherein,

[0062] Component A is a modified isocyanate mixture, specifically composed of polymethylene polyphenyl polyisocyanate (PAPI, isocyanate group content 30wt%): wherein,

[0063] Polymethylene polyphenyl polyisocyanate: mass 59.89 g.

[0064] Component B includes: polyether polyol, chain extender, deionized water, catalyst and surface tension regulator;

[0065] Among them, the quality of polyether polyol is taken as the benchmark.

[0066] The polyether polyol is polyethylene oxide-propylene copolymer triol with glycerol as the initiator, with a molecular weight of 3000 and a mass of 200g;

[0067] The chain extender is ethylene glycol, and the mass of the chain extender accounts for 3wt% of the total mass of the polyether polyol, i.e., 6g;

[0068] The mass of deionized water accounts for 0.5wt% of the total mass of the polyether polyol;

[0069] The catalyst is prepared by mixing 1g of bismuth isooctanoate and 1g of triethylenediamine, the mass of the catalyst accounts for 1wt% of the total mass of the polyether polyol, and the mass ratio of bismuth isooctanoate to triethylenediamine is 1:1;

[0070] The surface tension regulator is polydimethylsiloxane with a molecular weight of 1000, and the mass of the polydimethylsiloxane accounts for 2 wt % of the total mass of the polyether polyol, that is, 4 g.

[0071] Example 4

[0072] This embodiment 4 provides a method for preparing a compression-resistant polyurethane foam as in embodiment 3, the steps comprising:

[0073] Step 1: Mix component A and component B at 6000 rpm for 5 seconds to form a mixture;

[0074] Step 2: spray the mixture in step 1 onto a PET substrate at a thickness of 8 μm with 500 dot structures per square centimeter. After spraying, perform a first curing at a temperature of 100° C. to obtain a dot coating.

[0075] Step 3: Apply the mixture in step 1 to the surface of the dot coating with a thickness of 13 μm, and perform a second curing after the coating is completed. The second curing temperature is 85° C. to obtain a surface coating;

[0076] Step 4: Repeat steps 2 and 3 in sequence until there are 7 layers of dot coating and 8 layers of surface coating, and finally add one layer of surface coating. The total number of layers of dot coating and surface coating is 15, thereby obtaining polyurethane microcellular foam.

[0077] Step 5: Curing the polyurethane microporous foam at a temperature of 45° C. for 13 hours to obtain compression-resistant polyurethane foam.

[0078] Example 5

[0079] This embodiment 5 provides a compression-resistant polyurethane foam, comprising: component A and component B; wherein,

[0080] Component A is a modified isocyanate mixture, specifically composed of polymethylene polyphenyl polyisocyanate (PAPI, isocyanate group content 30wt%): wherein,

[0081] Polymethylene polyphenyl polyisocyanate: mass 86.21 g.

[0082] Component B includes: polyether polyol, chain extender, deionized water, catalyst and surface tension regulator;

[0083] Among them, the quality of polyether polyol is taken as the benchmark.

[0084] The polyether polyol is polyethylene oxide-propylene copolymer triol with glycerol as the initiator, with a molecular weight of 3000 and a mass of 200g;

[0085] The chain extender is ethylene glycol, and the mass of the chain extender accounts for 3wt% of the total mass of the polyether polyol, i.e., 6g;

[0086] The mass of deionized water accounts for 1wt% of the total mass of the polyether polyol;

[0087] The catalyst is prepared by mixing 1g of bismuth isooctanoate and 1g of triethylenediamine, the mass of the catalyst accounts for 1wt% of the total mass of the polyether polyol, and the mass ratio of bismuth isooctanoate to triethylenediamine is 1:1;

[0088] The surface tension regulator is polydimethylsiloxane with a molecular weight of 1000, and the mass of the polydimethylsiloxane accounts for 2 wt % of the total mass of the polyether polyol, that is, 4 g.

[0089] Example 6

[0090] This embodiment 6 provides a method for preparing a compression-resistant polyurethane foam as in embodiment 5, comprising the following steps:

[0091] Step 1: Mix component A and component B at 6000 rpm for 5 seconds to form a mixture;

[0092] Step 2: spray the mixture in step 1 onto a PET substrate at a thickness of 8 μm with 500 dot structures per square centimeter. After spraying, perform a first curing at a temperature of 110° C. to obtain a dot coating.

[0093] Step 3: Apply the mixture in step 1 to the surface of the dot coating with a thickness of 16 μm, and perform a second curing after the coating is completed. The second curing temperature is 90° C. to obtain a surface coating;

[0094] Step 4: Repeat steps 2 and 3 in sequence until there are 8 layers of dot coating, 8 layers of surface coating, and finally add one layer of surface coating. The total number of layers of dot coating and surface coating is 17, thereby obtaining a polyurethane microporous foam.

[0095] Step 5: Curing the polyurethane microporous foam at a temperature of 50° C. for 14 hours to obtain compression-resistant polyurethane foam.

[0096] Example 7

[0097] This embodiment 7 provides a compression-resistant polyurethane foam, comprising: component A and component B; wherein,

[0098] Component A is a modified isocyanate mixture, specifically composed of polymethylene polyphenyl polyisocyanate (PAPI, isocyanate group content 30wt%): wherein,

[0099] Polymethylene polyphenyl polyisocyanate: mass 73.88 g.

[0100] Component B includes: polyether polyol, chain extender, deionized water, catalyst and surface tension regulator;

[0101] Among them, the quality of polyether polyol is taken as the benchmark.

[0102] The polyether polyol is polyethylene oxide-propylene copolymer triol with glycerol as the initiator, with a molecular weight of 4000 and a mass of 200 g;

[0103] The chain extender is 1,4-butanediol (1,4-BG), and the mass of the chain extender accounts for 1wt% of the total mass of the polyether polyol, i.e., 2g;

[0104] The mass of deionized water accounts for 1.5wt% of the total mass of the polyether polyol;

[0105] The catalyst is prepared by mixing 1g of bismuth isooctanoate and 1g of triethylenediamine, the mass of the catalyst accounts for 1wt% of the total mass of the polyether polyol, and the mass ratio of bismuth isooctanoate to triethylenediamine is 1:1;

[0106] The surface tension regulator is polydimethylsiloxane with a molecular weight of 1000, and the mass of the polydimethylsiloxane accounts for 0.5 wt % of the total mass of the polyether polyol, that is, 1 g.

[0107] Example 8

[0108] This embodiment 8 provides a method for preparing a compression-resistant polyurethane foam as in embodiment 7, comprising the following steps:

[0109] Step 1: Mix component A and component B at 6000 rpm for 5 seconds to form a mixture;

[0110] Step 2: spray the mixture in step 1 onto a PET substrate at a thickness of 10 μm with 500 dot structures per square centimeter. After spraying, perform a first curing at a temperature of 120° C. to obtain a dot coating.

[0111] Step 3: Apply the mixture in step 1 to the surface of the dot coating with a thickness of 20 μm, and perform a second curing after the coating is completed. The temperature of the second curing is 100° C. to obtain a surface coating;

[0112] Step 4: Repeat steps 2 and 3 in sequence until there are 9 layers of dot coating, 9 layers of surface coating, and finally add one layer of surface coating. The total number of layers of dot coating and surface coating is 19, thus obtaining polyurethane microporous foam.

[0113] Step 5: Curing the polyurethane microporous foam at a temperature of 50° C. for 15 hours to obtain compression-resistant polyurethane foam.

[0114] Example 9

[0115] This embodiment 9 provides a compression-resistant polyurethane foam, comprising: component A and component B; wherein,

[0116] Component A is an isocyanate mixture, specifically composed of toluene diisocyanate (TDI) and isophorone diisocyanate (IPDI): wherein,

[0117] Toluene diisocyanate (TDI): mass 25.54g;

[0118] Isophorone diisocyanate (IPDI): mass 13.97 g;

[0119] The molar ratio of toluene diisocyanate (TDI) to isophorone diisocyanate (IPDI) is 7:3.

[0120] Component B includes: polyether polyol, chain extender, deionized water, catalyst and surface tension regulator;

[0121] Among them, the quality of polyether polyol is taken as the benchmark.

[0122] The polyether polyol is polyethylene oxide-propylene copolymer triol with glycerol as the initiator, with a molecular weight of 6000 and a mass of 200 g;

[0123] The chain extender is ethylene glycol (BG), and the mass of the chain extender accounts for 1.5wt% of the total mass of the polyether polyol, i.e., 3g;

[0124] The mass of deionized water accounts for 1wt% of the total mass of the polyether polyol;

[0125] The catalyst is prepared by mixing 1g of bismuth isooctanoate and 1g of triethylenediamine, the mass of the catalyst accounts for 1wt% of the total mass of the polyether polyol, and the mass ratio of bismuth isooctanoate to triethylenediamine is 1:1;

[0126] The surface tension regulator is polydimethylsiloxane with a molecular weight of 1000, and the mass of the polydimethylsiloxane accounts for 1 wt % of the total mass of the polyether polyol, that is, 2 g.

[0127] Example 10

[0128] This embodiment 10 provides a method for preparing a compression-resistant polyurethane foam as described in embodiment 9, comprising the following steps:

[0129] Step 1: Mix component A and component B at 6000 rpm for 5 seconds to form a mixture;

[0130] Step 2: spray the mixture in step 1 onto a PET substrate at a thickness of 10 μm with 1000 dot structures per square centimeter. After spraying, perform a first curing at a temperature of 100° C. to obtain a dot coating.

[0131] Step 3: Apply the mixture in step 1 to the surface of the dot coating with a thickness of 18 μm, and perform a second curing after the coating is completed. The second curing temperature is 110° C. to obtain a surface coating;

[0132] Step 4: Repeat steps 2 and 3 in sequence until there are 10 layers of dot coating, 10 layers of surface coating, and a total of 20 layers of dot coating and surface coating, thereby obtaining polyurethane microporous foam;

[0133] Step 5: Curing the polyurethane microporous foam at a temperature of 45° C. for 14 hours to obtain compression-resistant polyurethane foam.

[0134] Example 11

[0135] This embodiment 11 provides a method for preparing a compression-resistant polyurethane foam as in embodiment 1, comprising the following steps:

[0136] Step 1: Mix component A and component B at 6000 rpm for 5 seconds to form a mixture;

[0137] Step 2: spray the mixture in step 1 onto a polyurethane film at a thickness of 3 μm with 100 dot structures per square centimeter. After spraying, perform a first curing at a temperature of 90° C. to obtain a dot coating.

[0138] Step 3: Apply the mixture in step 1 to the surface of the dot coating with a thickness of 10 μm, and perform a second curing after the coating is completed. The temperature of the second curing is 80° C. to obtain a surface coating;

[0139] Step 4: Repeat steps 2 and 3 in sequence until the dot coating has 8 layers, the surface coating has 8 layers, and the total number of the dot coating and surface coating is 16 layers, thereby obtaining a polyurethane microporous foam.

[0140] Step 5: Curing the polyurethane microporous foam at a temperature of 40° C. for 12 hours to obtain compression-resistant polyurethane foam.

[0141] Comparative Example 1

[0142] This comparative example 1 provides a comparative sample of compression-resistant polyurethane foam, comprising: component A and component B; wherein,

[0143] Component A is an isocyanate mixture, specifically composed of toluene diisocyanate (TDI) and isophorone diisocyanate (IPDI): wherein,

[0144] Toluene diisocyanate (TDI): mass 59.89 g;

[0145] Isophorone diisocyanate (IPDI): mass 76.45 g;

[0146] The molar ratio of toluene diisocyanate (TDI) to isophorone diisocyanate (IPDI) is 1:1.

[0147] Component B includes: polyether polyol, chain extender, deionized water, catalyst and surface tension regulator;

[0148] Among them, the quality of polyether polyol is taken as the benchmark.

[0149] The polyether polyol is polyethylene oxide-propylene copolymer triol with glycerol as the initiator, with a molecular weight of 500 and a mass of 200 g;

[0150] The chain extender is ethylene glycol, and the mass of the chain extender accounts for 1wt% of the total mass of the polyether polyol, i.e., 2g;

[0151] The mass of deionized water accounts for 0.5wt% of the total mass of the polyether polyol;

[0152] The catalyst is prepared by mixing 1g of bismuth isooctanoate and 1g of triethylenediamine, the mass of the catalyst accounts for 1wt% of the total mass of the polyether polyol, and the mass ratio of bismuth isooctanoate to triethylenediamine is 1:1;

[0153] The surface tension regulator is polydimethylsiloxane with a molecular weight of 1000, and the mass of the polydimethylsiloxane accounts for 0.5 wt % of the total mass of the polyether polyol, that is, 1 g.

[0154] The preparation method of the above-mentioned compression-resistant polyurethane foam comparative sample comprises the following steps:

[0155] Step 1: Mix component A and component B at 6000 rpm for 5 seconds to form a mixture;

[0156] Step 2: spray the mixture in step 1 onto a PET substrate at a thickness of 3 μm with 100 dot structures per square centimeter, and then cure the mixture at a temperature of 90° C. to obtain a dot coating.

[0157] Step 3: Repeat step 2 in sequence until the dot coating reaches 20 layers, thus obtaining a semi-finished product;

[0158] Step 4: Curing the semi-finished product at 40°C for 13 hours and preparing for testing.

[0159] Comparative Example 2

[0160] This comparative example 2 provides a comparative sample of compression-resistant polyurethane foam, comprising: component A and component B; wherein,

[0161] Component A is an isocyanate mixture, specifically composed of toluene diisocyanate (TDI) and isophorone diisocyanate (IPDI): wherein,

[0162] Toluene diisocyanate (TDI): mass 22.64g;

[0163] Isophorone diisocyanate (IPDI): mass 67.42 g;

[0164] The molar ratio of toluene diisocyanate (TDI) to isophorone diisocyanate (IPDI) is 3:7.

[0165] Component B includes: polyether polyol, chain extender, deionized water, catalyst and surface tension regulator;

[0166] Among them, the quality of polyether polyol is taken as the benchmark.

[0167] The polyether polyol is polyethylene oxide-propylene copolymer triol with glycerol as the initiator, with a molecular weight of 1000 and a mass of 200 g;

[0168] The chain extender is 1,4-butanediol, and the mass of the chain extender accounts for 2wt% of the total mass of the polyether polyol, i.e., 4g;

[0169] The mass of deionized water accounts for 0.8wt% of the total mass of the polyether polyol;

[0170] The catalyst is prepared by mixing 1g of bismuth isooctanoate and 1g of triethylenediamine, the mass of the catalyst accounts for 1wt% of the total mass of the polyether polyol, and the mass ratio of bismuth isooctanoate to triethylenediamine is 1:1;

[0171] The surface tension regulator is polydimethylsiloxane with a molecular weight of 1000, and the mass of the polydimethylsiloxane accounts for 1 wt % of the total mass of the polyether polyol, that is, 2 g.

[0172] The preparation method of the above-mentioned compression-resistant polyurethane foam comparative sample comprises the following steps:

[0173] Step 1: Mix component A and component B at 6000 rpm for 5 seconds to form a mixture;

[0174] Step 2: coating the mixture in step 1 on a PET substrate with a thickness of 10 μm, and curing the mixture at a temperature of 100° C. to obtain a surface coating;

[0175] Step 3: Repeat step 2 in sequence until the surface coating has 20 layers, thus obtaining a semi-finished product;

[0176] Step 4: Curing the semi-finished product at 45°C for 12 hours and prepare for testing.

[0177] Comparative Example 3

[0178] This comparative example 3 provides a comparative sample of compression-resistant polyurethane foam, comprising: component A and component B; wherein,

[0179] Component A is a modified isocyanate mixture, specifically composed of polymethylene polyphenyl polyisocyanate (PAPI, isocyanate group content 30wt%): wherein,

[0180] Polymethylene polyphenyl polyisocyanate: mass 86.21 g.

[0181] Component B includes: polyether polyol, chain extender, deionized water, catalyst and surface tension regulator;

[0182] Among them, the quality of polyether polyol is taken as the benchmark.

[0183] The polyether polyol is polyethylene oxide-propylene copolymer triol with glycerol as the initiator, with a molecular weight of 3000 and a mass of 200g;

[0184] The chain extender is ethylene glycol, and the mass of the chain extender accounts for 3wt% of the total mass of the polyether polyol, i.e., 6g;

[0185] The mass of deionized water accounts for 1wt% of the total mass of the polyether polyol;

[0186] The catalyst is prepared by mixing 1g of bismuth isooctanoate and 1g of triethylenediamine, the mass of the catalyst accounts for 1wt% of the total mass of the polyether polyol, and the mass ratio of bismuth isooctanoate to triethylenediamine is 1:1;

[0187] The surface tension regulator is polydimethylsiloxane with a molecular weight of 1000, and the mass of the polydimethylsiloxane accounts for 2 wt % of the total mass of the polyether polyol, that is, 4 g.

[0188] The preparation method of the above-mentioned compression-resistant polyurethane foam comparative sample comprises the following steps:

[0189] Step 1: Mix component A and component B at 6000 rpm for 5 seconds to form a mixture;

[0190] Step 2: spray the mixture in step 1 onto a PET substrate at a thickness of 10 μm with 1000 dot structures per square centimeter. After spraying, perform a first curing at a temperature of 90° C. to obtain a dot coating, and continue until there are 10 layers of dot coating.

[0191] Step 3: Apply the mixture in step 1 to the surface of the dot coating with a thickness of 20 μm, and perform a second curing after coating at a temperature of 80° C. to obtain a surface coating, and continue until there are 10 layers of the surface coating;

[0192] The total number of layers of the dot coating and the surface coating is 20, thus obtaining a semi-finished product;

[0193] Step 5: Curing the semi-finished product at 50°C for 13 hours and prepare for testing.

[0194] The performance test indicators of Examples 2, 4, 6, 8, 10 and Comparative Examples 1 to 3 are shown in Table 1.

[0195] Test method:

[0196] (1) Test environment: temperature 23±2℃, RH 50±5%; sample size: 50mm*50mm*10mm (close to 10mm);

[0197] (2) The sample is compressed from its original thickness to 50% at a compression rate of 1 Hz. After 500,000 cycles of compression, the foam thickness before and after compression is tested.

[0198] Table 1 Compression resistance polyurethane foam performance test table

[0199]

[0200] As can be seen from Table 1, the compression-resistant polyurethane foams prepared in Examples 2, 4, 6, 8, and 10 all have good compression resistance and minimal thickness loss; while in the comparative example, the fatigue resistance and compression resistance of the foams prepared using the conventional method are relatively poor.

[0201] In summary, the present invention uses a two-component liquid raw material that is easy to mix and process, and creatively combines the spraying of a dot structure with the coating of a surface structure. That is, on a supporting film, a fixed number of dots are sprayed per unit area to prepare a dot-like coating. The dot-shaped polyurethane foam on the coating is inherently compressible, and there are gaps between the dots, which increases the compressible space. At the same time, a planar structure of a certain thickness is coated on the dot-shaped coating, and after curing, the coating layer forms a continuous and complete plane. The dot-surface structure is interwoven and arranged. When the number of layers reaches a certain number, a three-dimensional "dot-surface-dot-surface" structure is formed. When the surface layer is compressed, the microscopic polyurethane foam pores in the dot-surface act as countless tiny shock-absorbing units to absorb external compression energy. At the same time, the multi-layer dot-surface structure at the macro level can work together with the tiny bubble shock-absorbing units to offset the external compression force to the greatest extent, protecting the bubble wall from breaking due to large stress and repeated compression to the greatest extent, giving the material exceptionally excellent compression resistance.

[0202] The above are only preferred embodiments of the present invention and do not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A compression-resistant polyurethane foam, characterized in that: include: Component A, and component B; Wherein, the component A comprises: at least one of isocyanate or modified isocyanate; Wherein, the component B comprises: polyether polyol, chain extender, deionized water, catalyst and surface tension regulator; wherein, based on the mass of the polyether polyol, The mass of the chain extender accounts for 1wt%-3wt% of the total mass of the polyether polyol; The mass of the deionized water accounts for 0.5wt%-1.5wt% of the total mass of the polyether polyol; The mass of the catalyst accounts for 1wt%-2wt% of the total mass of the polyether polyol; The mass of the surface tension regulator accounts for 0.5 wt% to 2 wt% of the total mass of the polyether polyol.

2. The compression-resistant polyurethane foam according to claim 1, characterized in that: The isocyanate is at least one of toluene diisocyanate and isophorone diisocyanate, and the modified isocyanate is polymethylene polyphenyl polyisocyanate.

3. The compression-resistant polyurethane foam according to claim 2, characterized in that: The molar ratio of the toluene diisocyanate to the isophorone diisocyanate is 1:1-7:3, and the content of the isocyanate group in the polymethylene polyphenyl polyisocyanate is 30 wt %-50 wt %.

4. The compression-resistant polyurethane foam according to claim 1, characterized in that: The polyether polyol is an ethylene oxide (propylene) type polyether polyol, the chain extender is a diol, the catalyst is at least one of an organic metal catalyst or an amine catalyst, and the surface tension regulator is liquid silicone oil.

5. The compression-resistant polyurethane foam according to claim 4, characterized in that: The ethylene oxide (propylene) type polyether polyol is a polyoxyethylene-propylene copolymer triol with glycerol as an initiator; The diol is ethylene glycol or 1,4-butanediol; The organometallic catalyst is bismuth isooctanoate, and the amine catalyst is triethylenediamine; The liquid silicone oil is polydimethylsiloxane.

6. The compression-resistant polyurethane foam according to claim 5, characterized in that: The molecular weight of the polyethylene oxide-propylene copolyol is 500-6000, and the mass ratio of the bismuth isooctanoate to the triethylenediamine is 1:

1.

7. The method for preparing a compression-resistant polyurethane foam according to any one of claims 1 to 6, characterized in that the steps include: Step 1: Mix component A and component B at a mixing speed of 5000 rpm to 6000 rpm to form a mixture; Step 2: spraying the mixture in step 1 onto the substrate at a thickness of 3 μm to 10 μm with 100 to 1000 dot structures per square centimeter, and performing a first curing after the spraying is completed to obtain a dot coating; Step 3: applying the mixture in step 1 to the surface of the dot coating with a thickness of 10 μm-20 μm, and performing a second curing after the coating is completed to obtain a surface coating; Step 4: Repeat step 2 and step 3 in sequence until the dot coating has 7 to 10 layers, the surface coating has 7 to 10 layers, and the total number of layers of the dot coating and the surface coating is 14 to 20 layers, thereby obtaining a polyurethane microporous foam; Step 5: subjecting the polyurethane microporous foam to a aging treatment to obtain compression-resistant polyurethane foam.

8. The method for preparing compression-resistant polyurethane foam according to claim 7, characterized in that: The mixing time of the component A and the component B is 5s-10s, the temperature of the first curing is 90°C-120°C, and the temperature of the second curing is 80°C-110°C.

9. The method for preparing compression-resistant polyurethane foam according to claim 7, characterized in that: The temperature of the aging treatment in step 5 is 40° C.-50° C., and the time of the aging treatment is 12 h-15 h.

10. The method for preparing compression-resistant polyurethane foam according to claim 7, characterized in that: The substrate in step 2 is a polyurethane film or a PET substrate.

Images