Foaming agent composition, rigid polyurethane thermal insulation material, preparation method of rigid polyurethane thermal insulation material and refrigerator

Abstract

The invention discloses a foaming agent composition, a rigid polyurethane thermal insulation material, a preparation method of the rigid polyurethane thermal insulation material and a refrigerator, and belongs to the technical field of thermal insulation materials. According to the technical scheme, the foaming agent comprises a high-boiling-point foaming agent, a medium-boiling-point foaming agent and a low-boiling- The high-boiling-point foaming agent comprises cyclopentane and dimethyl formal; the boiling point of the medium-boiling-point foaming agent is lower than that of the high-boiling-point foaming agent and higher than 10 DEG C The boiling point of the low-boiling-point foaming agent is less than 0 DEG The dosage of the high-boiling-point foaming agent is greater than that of the medium-boiling-point foaming agent and the low-boiling-point foaming agent The rigid polyurethane heat insulation material is applied to the aspect of heat insulation materials, and the problems that an existing rigid polyurethane heat insulation material cannot give consideration to good heat insulation performance, the filling density is low and the demolding efficiency is low are solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of thermal insulation materials, and particularly relates to a foaming agent composition, a rigid polyurethane thermal insulation material, a preparation method thereof, and a refrigerator. BACKGROUND

[0002] At present, with the tightening of environmental protection regulations, the hydrogen fluoride chlorocarbon foaming agent CFCs, HCFCs, etc. used in refrigerators and freezers are replaced by pentane and HFOs, a kind of fluorinated olefin, which has become the mainstream foaming agent. However, with the further improvement of environmental protection requirements, HFCs are further restricted due to high greenhouse effect potential, and the main HFO foaming agents in the industry, such as HFO-1233zd and HFO-1336mzz, are prohibited on refrigerators from January 1, 2026 due to the latest EU F-GAS regulation. Green low carbon, energy saving and resource saving have become the trend of technological development.

[0003] Pentane foaming agent has wide sources and low price, but its thermal conductivity is high, and it is flammable and explosive. In addition, due to the high boiling point of cyclopentane, a large amount of foaming raw materials is consumed when it is used alone. HFOs are the fourth generation of environmentally friendly foaming agents, but the cost is high when they are used alone. Moreover, HFO-1233zd and HFO-1336mzz used in the industry at present are prone to degrade to produce trifluoroacetic acid (TFA) in the atmosphere, and TFA is identified as a permanent compound (PFAS) by the scientific community. Methyl formate and HFOs belong to the fourth generation of environmentally friendly physical foaming agents, and have the advantages of low cost and good environmental protection. However, methyl formate has strong solvation effect and is easy to hydrolyze, and the polyurethane foam prepared thereby is prone to shrinkage and has poor dimensional stability.

[0004] In order to reduce the density of rigid polyurethane foam, some manufacturers use low-boiling-point foaming agents with a boiling point lower than 0℃ to reduce the density by using the characteristics of high vapor pressure and low boiling point, thereby reducing the amount of foaming raw materials and the cost. However, due to the low solubility of low-boiling-point foaming agents in the combined polyether, they are easy to volatilize. On the one hand, the amount of low-boiling-point foaming agents added in the combined polyether is limited. On the other hand, the rapid volatilization takes away a lot of reaction heat, and due to the high vapor pressure, it is easy to cause foaming quality problems, such as bubbles, "bulging delamination" of the metal back plate, etc. In addition, in order to improve the production capacity, refrigerator manufacturers have begun to significantly shorten the demolding time of the refrigerator foaming process to improve production efficiency. However, since the preparation of rigid polyurethane foam is an organic chemical reaction, demolding before the maturation is completed is easy to cause "bulging" or even "delamination" between the base material of the refrigerator and the foam, causing consumer complaints or a decrease in thermal insulation performance. SUMMARY

[0005] In view of the deficiencies of the prior art, the technical problem to be solved by the present application is that the existing rigid polyurethane thermal insulation material cannot simultaneously have good thermal insulation performance, low filling density and high demolding efficiency, and the present application provides a foaming agent composition, a rigid polyurethane thermal insulation material, a preparation method thereof and a refrigerator, which have good thermal insulation performance, low filling density and high demolding efficiency.

[0006] To solve the technical problem, the technical scheme adopted by the present application is: The present application provides a foaming agent composition, which comprises a high-boiling-point foaming agent, a medium-boiling-point foaming agent and a low-boiling-point foaming agent. The high-boiling-point foaming agent comprises cyclopentane and dimethylol formaldehyde. The boiling point of the medium-boiling-point foaming agent is less than the boiling point of the high-boiling-point foaming agent and greater than 10 DEG C, and the boiling point of the low-boiling-point foaming agent is less than 0 DEG C. The amount of the high-boiling-point foaming agent is greater than the amounts of the medium-boiling-point foaming agent and the low-boiling-point foaming agent.

[0007] In some embodiments, the medium-boiling-point foaming agent is trimethylfluorosilane, and the low-boiling-point foaming agent is selected from butane and / or 1,2-difluoroethylene.

[0008] In some embodiments, the amount of the high-boiling-point foaming agent is selected from any value in the range of 12-18 parts by mass, the amount of the medium-boiling-point foaming agent is selected from any value in the range of 1-5 parts by mass, and the amount of the low-boiling-point foaming agent is selected from any value in the range of 1-5 parts by mass; the high-boiling-point foaming agent comprises 11-15 parts of cyclopentane and 1.5-3.5 parts of dimethylol formaldehyde.

[0009] The present application provides a rigid polyurethane thermal insulation material, which comprises a combined polyether, an organic polyisocyanate and the foaming agent composition of any one of the above.

[0010] In some embodiments, the rigid polyurethane thermal insulation material further comprises water, a foam stabilizer, a catalyst and an additive.

[0011] In some embodiments, the amount of the combined polyether is selected from 100 parts by mass, the amount of the organic polyisocyanate is selected from any value in the range of 135-148 parts by mass, the amount of the foaming agent composition is selected from any value in the range of 16-21 parts by mass, the amount of the water is selected from any value in the range of 2.1-2.4 parts by mass, the amount of the foam stabilizer is selected from any value in the range of 2.5-3.5 parts by mass, the amount of the catalyst is selected from any value in the range of 2.1-2.5 parts by mass, and the amount of the additive is selected from any value in the range of 1-3 parts by mass.

[0012] In some embodiments, the combined polyether is prepared by mixing a polyether polyol A, a polyether polyol B, a polyether polyol C and a polyester polyol D. The average functionality of the polyether polyol A is 6.0, and the hydroxyl value is 400-480 mgKOH / g; the average functionality of the polyether polyol B is 3.5, and the hydroxyl value is 330-420 mgKOH / g; the average functionality of the polyether polyol C is 4.6, and the hydroxyl value is 400-450 mgKOH / g; the average functionality of the polyester polyol D is 2.5, and the hydroxyl value is 250-350 mgKOH / g; The amount of the polyether polyol A is selected from any value in 25-40 parts; the amount of the polyether polyol B is selected from any value in 20-35 parts; the amount of the polyether polyol C is selected from any value in 10-30 parts; and the amount of the polyester polyol D is selected from any value in 10-30 parts.

[0013] In some embodiments, the foam stabilizer is a silicone oxane polyoxyalkylene graft copolymer; the catalyst is a composite catalyst system of tertiary amines and organic tin, including a foaming catalyst, a gelation catalyst and a trimerization catalyst; the additive is a cyclic ester compound; and the organic polyisocyanate is a polymethylene polyphenyl polyisocyanate.

[0014] The application also provides a preparation method of the rigid polyurethane thermal insulation material of any one of the above, comprising: S1: uniformly mixing the combined polyether, the high-boiling foaming agent, the medium-boiling foaming agent and the additive at a material temperature of 15-20℃ to obtain a mixed white material; S2: liquefying the low-boiling foaming agent into a liquid low-boiling foaming agent by high pressure at a material temperature of 15-20℃, and injecting the liquid low-boiling foaming agent into the premixing tank; S3: mixing and foaming the mixed white material, the liquid low-boiling foaming agent and the organic polyisocyanate by high pressure through a high-pressure foaming gun head, and injecting the mixture into a refrigerator mold preheated to 35-45℃ to prepare a polyurethane foam, wherein the pressure of the gun head is 110-160 bar.

[0015] The application also provides a refrigerator adopting the rigid polyurethane thermal insulation material of any one of the above.

[0016] Compared with the prior art, the application has the following beneficial effects: The application provides a foaming agent composition, which adopts foaming agents with different boiling points, and the eutectic or quasi-eutectic mixture formed by mixing the foaming agents with different boiling points has a synergistic effect when foaming polyurethane, so that the prepared foam has a low thermal conductivity (0.01900 W / m.K or lower), a significantly reduced density (the density is reduced to 27.0-27.5 kg / m 3 ), reduced foaming raw materials, reduced cost, and improved production efficiency of the foaming process. DETAILED DESCRIPTION

[0017] The technical solutions in the specific embodiments of the present application will be described in detail below. Obviously, the described embodiments are only part of the specific implementations of the general technical solutions of the present application, but not all the implementations. Based on the general concept of the present application, all other embodiments obtained by those skilled in the art fall within the scope of protection of the present application.

[0018] A blowing agent composition includes a high-boiling blowing agent.

[0019] In some embodiments, the high-boiling blowing agent includes cyclopentane.

[0020] Pentane blowing agent has a wide source and low price, but its thermal conductivity is high, and it is flammable and explosive. Since the boiling point of cyclopentane is high, a large amount of blowing raw materials is consumed when it is used alone.

[0021] In some embodiments, the high-boiling blowing agent includes dimethylformaldehyde.

[0022] Dimethylformaldehyde has some properties similar to methyl formate, is an excellent solvent for polyurethane, can reduce the viscosity of polyol, improve the miscibility of polyether component and the uniformity of foam, but its chemical properties are more stable than methyl formate, and it is not easy to hydrolyze and oxidize. In addition, dimethylformaldehyde can also reduce the pressure generated by other blowing agents, so it is beneficial to the demolding of the product and the adhesion between the reinforcing substrate and the foam.

[0023] It should be noted that the addition of dimethylformaldehyde, on the one hand, the viscosity of dimethylformaldehyde itself is low, which can reduce the viscosity of the polyol of the oligomer, improve the solubility and uniformity of other blowing agents, especially in the combined polyether, and improve the flowability of the raw materials. On the other hand, the dimethylformaldehyde molecule contains a strong polar group, which can react with the amino group to form a hydrogen bond, which is beneficial to enhance the strength and dimensional stability of the foam, and to enhance the skeleton strength of the foam. Trimethylfluorosilane and low-boiling blowing agent have the problems of difficult dispersion and uneven dispersion. According to a specific proportion, they can be used together to promote the compatibility of trimethylfluorosilane and low-boiling blowing agent with the polyurethane raw material system, thereby improving the dispersion effect, fully exerting the nucleation function of trimethylfluorosilane and the anti-compression deformation ability of low-boiling blowing agent, thereby improving the thermal conductivity and reducing the density of the foam. It can also reduce the pressure generated by the boiling agent, which is beneficial to reduce the volatilization of the blowing agent, especially the low-boiling blowing agent, and to reduce the cell size, so it is beneficial to further improve the thermal insulation performance of the foam and the adhesion between the foam and the metal surface.

[0024] A blowing agent composition includes a medium-boiling blowing agent, the boiling point of the medium-boiling blowing agent is less than the boiling point of the high-boiling blowing agent, and greater than 10℃. In some embodiments, the medium-boiling blowing agent is trimethylfluorosilane, and the boiling point is 16.5℃.

[0025] A blowing agent composition, including a low-boiling blowing agent, the low-boiling blowing agent having a boiling point less than 0°C.

[0026] The present application utilizes the dual physical properties of rapid gas expansion and high-efficiency evaporation heat absorption of low-boiling blowing agents. On the one hand, with the assistance of a synergistic system, a significant reduction in foam density (<27.0 kg / m 3 ) and a good balance of dimensional stability are achieved, resulting in significant material cost savings. On the other hand, by rapidly volatilizing a large amount of reaction heat, the peak reaction temperature is effectively controlled, significantly shortening the time required for foam curing and demolding, thereby significantly improving the overall production efficiency of the foaming process, product quality, and mold durability.

[0027] A blowing agent composition, the amount of high-boiling blowing agent is greater than the amount of medium-boiling blowing agent, and the amount of low-boiling blowing agent.

[0028] In some embodiments, the low-boiling blowing agent is selected from butane.

[0029] In some embodiments, the low-boiling blowing agent is selected from 1,2-difluoroethylene. 1,2-Difluoroethylene (HFO-1132) does not contain -CF3, -CF2, and will not degrade into trifluoroacetic acid.

[0030] The addition of low-boiling blowing agents butane and 1,2-difluoroethylene utilizes the dual physical properties of rapid gas expansion and high-efficiency evaporation heat absorption of low-boiling blowing agents. On the one hand, with the assistance of a synergistic system, a significant reduction in foam density (<27.0 kg / m 3 ) and a good balance of dimensional stability are achieved, resulting in significant material cost savings. On the other hand, by rapidly volatilizing a large amount of reaction heat, the peak reaction temperature is effectively controlled, significantly shortening the time required for foam curing and demolding, thereby significantly improving the overall production efficiency of the foaming process, product quality, and mold durability.

[0031] The present application uses high-boiling cyclopentane as the main blowing agent, and by adding an appropriate amount of environmentally friendly, low-gas thermal conductivity medium and low-boiling blowing agents, the thermal conductivity of the insulating foam layer is improved, the density of the foam is reduced, the raw materials for foaming are reduced, the cost of the product is reduced, and the production efficiency of the foaming process is improved. Different boiling point composite blowing agent system is adopted, high boiling point (>40℃) blowing agent adopts cyclopentane and dimethylol formaldehyde, medium boiling point (10-20℃) blowing agent adopts trimethylfluorosilane, and low boiling point blowing agent (<0℃) adopts at least one of butane (n-butane, isobutane) and 1,2-difluoroethylene. The azeotrope or azeotrope-like mixture formed by mixing different boiling point blowing agents has a synergistic effect when foaming polyurethane, and the prepared foam has low thermal conductivity (0.01900 W / m.K or lower) and significantly reduced density (density reduced to 27.0 kg / m 3), reducing the foaming raw material, thus being beneficial to reduce the cost.

[0032] In some embodiments, the high-boiling-point blowing agent is used in an amount selected from any value in the range of 12-18 parts by mass. It can be understood that the high-boiling-point blowing agent can also be used in an amount of 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, and any point value in the range thereof.

[0033] In some embodiments, the medium-boiling-point blowing agent is used in an amount selected from any value in the range of 1-5 parts by mass. It can be understood that the medium-boiling-point blowing agent can also be used in an amount of 2 parts, 3 parts, 4 parts, and any point value in the range thereof.

[0034] In some embodiments, the low-boiling-point blowing agent is used in an amount selected from any value in the range of 1-5 parts by mass. It can be understood that the low-boiling-point blowing agent can also be used in an amount of 2 parts, 3 parts, 4 parts, and any point value in the range thereof.

[0035] In some embodiments, the high-boiling-point blowing agent includes 11-15 parts of cyclopentane by mass. It can be understood that the amount of cyclopentane can also be 12 parts, 13 parts, 14 parts, and any point value in the range thereof.

[0036] In some embodiments, the high-boiling-point blowing agent includes 1.5-3.5 parts of dimethylformal by mass. It can be understood that the amount of dimethylformal can also be 2.0 parts, 2.5 parts, 3.0 parts, and any point value in the range thereof.

[0037] A rigid polyurethane thermal insulation material includes a combined polyether.

[0038] In some embodiments, the combined polyether is made by mixing polyether polyol A, polyether polyol B, polyether polyol C, and polyester polyol D.

[0039] The average functionality of the polyether polyol A is 6.0, and the hydroxyl value is 400-480 mgKOH / g; the average functionality of the polyether polyol B is 3.5, and the hydroxyl value is 330-420 mgKOH / g; the average functionality of the polyether polyol C is 4.6, and the hydroxyl value is 400-450 mgKOH / g; the average functionality of the polyester polyol D is 2.5, and the hydroxyl value is 250-350 mgKOH / g. A rigid polyurethane thermal insulation material includes an organic polyisocyanate.

[0040] In some embodiments, the organic polyisocyanate is a polymethylene polyphenyl polyisocyanate, such as PAPI 27 from DOW, Bayhydur® 44V-20L from Bayer, Desmodur® M20S from BASF, Suprasec-5005 from Huntsman, PM2010 from Yantai Wanhua, PM200 from Yantai Wanhua.

[0041] A rigid polyurethane thermal insulation material includes a blowing agent composition. The rigid polyurethane thermal insulation material has good thermal insulation performance, low filling density, good adhesion between the rigid polyurethane foam and the substrate, good mechanical properties, and high demolding efficiency. The blowing agent composition has an ODP of 0 for all components, a GWP value less than 15, is environmentally friendly, has good environmental protection, meets domestic and foreign environmental protection regulations, and meets the needs of future development.

[0042] A rigid polyurethane thermal insulation material includes water.

[0043] A rigid polyurethane thermal insulation material includes a foam stabilizer. In some embodiments, the foam stabilizer is an organosiloxane polyoxyalkylene graft copolymer; and can be selected from one or a mixture of several of B8462, B8510, B8545, L6863, L6952.

[0044] A rigid polyurethane thermal insulation material includes a catalyst. In some embodiments, the catalyst is a composite catalyst system of tertiary amines and organotin, including a blowing catalyst, a gel catalyst, and a trimerization catalyst; wherein the blowing catalyst is at least one selected from bis-dimethylaminoethyl ether (A-1), pentamethyldiethylene triamine (PC-5), N-methyl dicyclohexylamine (PC-12), modified bis(dimethylaminoethyl) ether (BDMAEE), and tetramethylhexanediamine (TMHDA); the gel catalyst is at least one selected from dimethylcyclohexylamine (PC-8), 1,2-dimethylimidazole (DMI), and dimethylbenzylamine (BDMA); and the trimerization catalyst is at least one selected from (2-hydroxypropyl)trimethylammonium formate (TMR-2), tris(dimethylaminopropyl)hexahydrotriazine (PC-41), and 2,4,6-tris(dimethylaminomethyl)phenol (TMR-30).

[0045] In some embodiments, the catalyst is PC-5, PC-8, PC-41, and TMR-2. Among them, PC-41 and TMR-2 belong to a composite trimerization catalyst, and the combination of the two makes the foam have better post-ripening ability and compression strength. The catalyst system makes the entire reaction process more balanced, provides excellent flow dispersion performance for the polyurethane foam system, enhances the obstacle bypassing and passing ability of the foam, and shortens the demolding time.

[0046] A rigid polyurethane insulation material includes an additive. In some embodiments, the additive is a cyclic ester compound to increase the adhesion between the foam and the substrate. In some embodiments, the additive is Momentive Y-16350, which contains special siloxane branches that form strong hydrogen bonds, which can strengthen the bridging action between the metal substrate and the polyurethane foam, thereby enhancing the adhesion.

[0047] As the production capacity of the refrigerator and freezer is increased (shortening the product demolding time) and the filling density is reduced (reducing the cost of foaming raw materials, reducing the density, and reducing the adhesion of the foam and the substrate, especially the metal back), the product metal back plate and the internal foam are often separated from the "bulge" phenomenon, therefore, the additive is added as an adhesion promoter (Momentive Y-16350) in the present application, which is beneficial to improve the adhesion of rigid polyurethane and substrate, especially the metal back plate. The addition of the additive, combined with the adjustment and optimization of the polyether formula, ensures the good thermal insulation performance and ultra-low density of the foam, on the one hand, it is beneficial to shorten the demolding time of the product foaming process, and it is beneficial to improve the production efficiency of the product, on the other hand, it makes the rigid polyurethane foam and the substrate, especially the metal back plate, have good adhesion, which is beneficial to ensure the appearance quality of the product.

[0048] In some embodiments, the amount of the polyether combination is selected from 100 parts by mass.

[0049] In some embodiments, the amount of the organic polyisocyanate is selected from any value in the range of 135-148 parts by mass. It can be understood that the amount of the organic polyisocyanate can also be 136 parts, 137 parts, 138 parts, 139 parts, 140 parts, 141 parts, 142 parts, 143 parts, 144 parts, 145 parts, 146 parts, 147 parts, and any point value within the range thereof.

[0050] In some embodiments, the amount of the blowing agent composition is selected from any value in the range of 16-21 parts by mass. It can be understood that the amount of the blowing agent composition can also be 17 parts, 18 parts, 19 parts, 20 parts, and any point value within the range thereof.

[0051] In some embodiments, the amount of water is selected from any value in the range of 2.1-2.4 parts by mass. It can be understood that the amount of water can also be 2.2 parts, 2.3 parts, and any point value within the range thereof.

[0052] In some embodiments, the amount of the foam stabilizer is selected from any value in the range of 2.5-3.5 parts by mass. It can be understood that the amount of the foam stabilizer can also be 2.6 parts, 2.7 parts, 2.8 parts, 2.9 parts, 3.0 parts, 3.1 parts, 3.2 parts, 3.3 parts, 3.4 parts, and any point value within the range thereof.

[0053] In some embodiments, the amount of catalyst is selected from any value in the range of 2.1-2.5 parts by mass. It is understood that the amount of catalyst can also be 2.2 parts, 2.3 parts, 2.4 parts, and any point value within the range thereof.

[0054] In some embodiments, the amount of additive is selected from any value in the range of 1-3 parts by mass. It is understood that the amount of additive can also be 1.5 parts, 2.0 parts, 2.5 parts, and any point value within the range thereof.

[0055] In some embodiments, the amount of the combined polyether is 100 parts by mass, the amount of the organic polyisocyanate is 145 parts, and the amount of the blowing agent composition is 17.5 parts.

[0056] In some embodiments, the amount of polyether polyol A is selected from any value in the range of 25-40 parts by mass. It is understood that the amount of polyether polyol A can also be 28 parts, 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, and any point value within the range thereof.

[0057] In some embodiments, the amount of polyether polyol B is selected from any value in the range of 20-35 parts by mass. It is understood that the amount of polyether polyol B can also be 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, and any point value within the range thereof.

[0058] In some embodiments, the amount of polyether polyol C is selected from any value in the range of 10-30 parts by mass. It is understood that the amount of polyether polyol C can also be 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, and any point value within the range thereof.

[0059] In some embodiments, the amount of polyester polyol D is selected from any value in the range of 10-30 parts by mass. It is understood that the amount of polyester polyol D can also be 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, and any point value within the range thereof.

[0060] A method for preparing a rigid polyurethane thermal insulation material, comprising: S1: uniformly mixing the combined polyether, the high-boiling blowing agent, the medium-boiling blowing agent, and the additive at a material temperature of 15-20°C to obtain a mixed white material.

[0061] S2: liquefying the low-boiling blowing agent into a liquid low-boiling blowing agent by high pressure at a material temperature of 15-20°C, and injecting the liquid low-boiling blowing agent into a premixing tank; the low-boiling blowing agent is mixed with other raw materials through high pressure at the gun head, which can effectively improve the uniformity of the low-boiling blowing agent.

[0062] S3: Under the condition that the material temperature is 15-20℃, the mixed white material, liquid low-boiling foaming agent and organic polyisocyanate are mixed by high pressure and then injected into the preheated refrigerator mold at 35-45℃ to carry out mixed foaming, the pressure of the gun head is 110-160bar, and a polyurethane foam is prepared.

[0063] The application also provides a refrigerator using the rigid polyurethane thermal insulation material according to any one of the above.

[0064] In order to more clearly and specifically introduce the foaming agent composition, the rigid polyurethane thermal insulation material, the preparation method thereof and the refrigerator provided by the embodiments of the application, the following will be described in combination with specific embodiments.

[0065] Embodiment 1 1, Formula composition: 35 parts of polyether polyol A, 30 parts of polyether polyol B, 25 parts of polyether polyol C, 20 parts of polyester polyol D, 2.2 parts of water, 2.8 parts of foam stabilizer, 2.2 parts of catalyst, 1.5 parts of additive, 12.5 parts of cyclopentane, 1.5 parts of dimethylol formaldehyde, 5.5 parts of trimethyl fluorosilane, 2.0 parts of butane, and 156 parts of organic polyisocyanate.

[0066] The average functionality of the polyether polyol A is 6.0, and the hydroxyl value is 400mgKOH / g; the average functionality of the polyether polyol B is 3.5, and the hydroxyl value is 330mgKOH / g; the average functionality of the polyether polyol C is 4.6, and the hydroxyl value is 400mgKOH / g; the average functionality of the polyester polyol D is 2.5, and the hydroxyl value is 250mgKOH / g; The foam stabilizer is B8462; the catalyst is PC-5, PC-8, PC-41 and TMR-2; the additive is Y-16350 of MEGUIRE Company; and the organic polyisocyanate is PAPI27 of DOW Company.

[0067] 2, Preparation process: S1: Under the condition that the material temperature is 15℃, the combined polyether, high-boiling foaming agent, medium-boiling foaming agent and additive are uniformly mixed in proportion to obtain mixed white material; S2: Under the condition that the material temperature is 15℃, the low-boiling foaming agent is liquefied into liquid foaming agent by high pressure and then injected into a premixing tank; S3: Under the condition that the material temperature is 15℃, the mixed white material, liquid low-boiling foaming agent and polyisocyanate are mixed by high pressure and then injected into the preheated refrigerator mold at 35℃ to carry out mixed foaming, the pressure of the gun head is 110bar, and a polyurethane foam is prepared; S4: Within a specified time, the refrigerator is demolded from the mold and then related tests are carried out.

[0068] Example 2 The same as example 1, except that the formulation composition is different, see Table 1 for details.

[0069] Example 3 The same as example 1, except that the formulation composition is different, see Table 1 for details.

[0070] Example 4 The same as example 1, except that the formulation composition is different, see Table 1 for details.

[0071] Example 5 The same as example 1, except that the formulation composition is different, see Table 1 for details.

[0072] Example 6 The same as example 1, except that the formulation composition is different, see Table 2 for details.

[0073] Comparative Example 1 The same as example 1, except that the formulation composition is different, see Table 2 for details.

[0074] Comparative Example 2 The same as example 1, except that the formulation composition is different, see Table 2 for details.

[0075] Comparative Example 3 The same as example 1, except that the formulation composition is different, see Table 2 for details.

[0076] Comparative Example 4 The same as example 1, except that the formulation composition is different, see Table 2 for details.

[0077] Comparative Example 5 The same as example 1, except that the formulation composition is different, see Table 2 for details.

[0078] Comparative Example 6 The same as example 1, except that the formulation composition is different, see Table 2 for details.

[0079] Comparative Example 7 The same as example 1, except that the formulation composition is different, see Table 2 for details.

[0080] Among them, comparative example 1 is a foam prepared without adding dimethylalcohol formaldehyde; comparative example 2 is a foam prepared without adding a cyclic ester additive; comparative example 3 is a foam prepared without adding dimethylalcohol formaldehyde and a cyclic ester additive; comparative example 4 is a foam prepared without adding a low boiling point blowing agent; comparative example 5 and comparative example 6 are foams prepared outside the use amount range of the blowing agent; and comparative example 7 is a foam prepared by using a common tackifier.

[0081] Performance test The performance test standards are all determined according to national standards: Molded core density: GB / T 6343-2009; Compression strength: GB / T 8813-2008; Thermal conductivity: GB / T 10295-2008; Dimensional stability: GB / T 8811-2008; Adhesion test: using an electronic universal testing machine, the substrate is peeled off from the polyurethane foam, and the maximum force value required for the substrate to be peeled off from the surface of the polyurethane foam; Density distribution range: multiple rigid polyurethane foams are taken from different parts of the product for core density test, and the difference between the maximum value and the minimum value is the density distribution.

[0082] The raw material component content and the box body foam performance are shown in Tables 1 and 2.

[0083] Table 1 Raw material component content and box body foam performance of examples

[0084] Table 2 Raw material component content and box body foam performance of comparative examples

[0085] Foaming agent dosage relationship: since cyclopentane has low cost, it is used as the main foaming agent, dimethylformaldehyde is used to enhance the compatibility and dispersion effect of trimethylfluorosilane and low-boiling-point foaming agent, trimethylfluorosilane is used as a nucleating agent, too little dosage will not show effect, and too much dosage will still cause agglomeration; the low-boiling-point foaming agent is easy to volatilize due to its low boiling point, and too much dosage will affect the thermal conductivity and foaming quality.

[0086] As can be seen from the foam performance test results in Table 1, the foam prepared by using the technical solution provided by the present application has excellent comprehensive performance, the foaming agent is environmentally friendly and friendly to the environment, the foam has good flowability and density distribution in the product while ensuring low thermal conductivity of the foam, and the foam and the product substrate have good adhesion, in addition, under the same process parameter conditions, the use of the technical solution of the present application can effectively reduce the dosage of foaming raw materials, reduce the foam density, thereby reducing the cost, and can shorten the demolding time, which is conducive to improving the production efficiency of the product.

[0087] From the comparison of the data in the table, it can be seen that, compared with Comparative Example 1 without adding dimethylalcohol formaldehyde, although the density is reduced and the cohesiveness is good, the density distribution uniformity is poor, the thermal conductivity is increased, and the demolding efficiency is affected; compared with Comparative Example 2 without adding cyclic ester additive, although the fluidity is good and the density is reduced, the cohesiveness between the foam and the substrate is poor and the demolding efficiency is affected; compared with Comparative Example 3 with dimethylalcohol formaldehyde and cyclic ester additive, although the density is reduced, other performances are obviously poor; compared with Comparative Example 4 without using low-boiling-point foaming agent, the thermal conductivity is low, the cohesiveness is good, but the fluidity is poor, the density is high, and the demolding time is slow.

Claims

1. A blowing agent composition characterized in that, Comprising: high-boiling blowing agent, medium-boiling blowing agent, and low-boiling blowing agent; the high-boiling blowing agent comprises cyclopentane and dimethylalcohol formaldehyde; the medium-boiling blowing agent has a boiling point less than that of the high-boiling blowing agent and greater than 10℃; the low-boiling blowing agent has a boiling point less than 0℃; the high-boiling blowing agent is used in an amount greater than that of the medium-boiling blowing agent and the low-boiling blowing agent.

2. The blowing agent composition of claim 1, wherein, the medium-boiling blowing agent is trimethylfluorosilane; the low-boiling blowing agent is selected from butane and / or 1,2-difluoroethylene.

3. The blowing agent composition of claim 1, wherein, the high-boiling blowing agent is used in an amount selected from any value in the range of 12-18 parts by mass, the medium-boiling blowing agent is used in an amount selected from any value in the range of 1-5 parts by mass, and the low-boiling blowing agent is used in an amount selected from any value in the range of 1-5 parts by mass; the high-boiling blowing agent comprises 11-15 parts of cyclopentane and 1.5-3.5 parts of dimethylalcohol formaldehyde.

4. A rigid polyurethane thermal insulation material, characterized by, Comprising: combined polyether, organic polyisocyanate, and the blowing agent composition according to any one of claims 1-3.

5. The rigid polyurethane thermal insulation material according to claim 4, characterized in that Further comprising: water, foam stabilizer, catalyst, additive.

6. The rigid polyurethane thermal insulation material according to claim 5, characterized in that the combined polyether is used in an amount selected from 100 parts by mass, the organic polyisocyanate is used in an amount selected from any value in the range of 135-148 parts by mass, the blowing agent composition is used in an amount selected from any value in the range of 16-21 parts by mass, the water is used in an amount selected from any value in the range of 2.1-2.4 parts by mass, the foam stabilizer is used in an amount selected from any value in the range of 2.5-3.5 parts by mass, the catalyst is used in an amount selected from any value in the range of 2.1-2.5 parts by mass, and the additive is used in an amount selected from any value in the range of 1-3 parts by mass.

7. The rigid polyurethane thermal insulation material according to claim 6, characterized in that the combined polyether is prepared by mixing polyether polyol A, polyether polyol B, polyether polyol C, and polyester polyol D; the polyether polyol A has an average functionality of 6.0 and a hydroxyl value of 400-480 mgKOH / g; the polyether polyol B has an average functionality of 3.5 and a hydroxyl value of 330-420 mgKOH / g; the polyether polyol C has an average functionality of 4.6 and a hydroxyl value of 400-450 mgKOH / g; and the polyester polyol D has an average functionality of 2.5 and a hydroxyl value of 250-350 mgKOH / g; the polyether polyol A is used in an amount selected from any value in the range of 25-40 parts by mass; the polyether polyol B is used in an amount selected from any value in the range of 20-35 parts by mass; the polyether polyol C is used in an amount selected from any value in the range of 10-30 parts by mass; and the polyester polyol D is used in an amount selected from any value in the range of 10-30 parts by mass.

8. The rigid polyurethane thermal insulation material according to claim 5, characterized in that, the foam stabilizer is organosiloxane polyoxyalkylene graft copolymer; the catalyst is a composite catalyst system of tertiary amine and organic tin, comprising blowing catalyst, gelling catalyst, and trimerization catalyst; the additive is cyclic ester compound; and the organic polyisocyanate is polymethylene polyphenyl polyisocyanate.

9. Process for the production of rigid polyurethane thermal insulation according to any one of claims 4 to 8, characterized in that, Comprising: S1: uniformly mix the combined polyether, high-boiling blowing agent, medium-boiling blowing agent, and additive at a material temperature of 15-20℃ to obtain a mixed white material; S2: liquefy the low-boiling blowing agent into liquid low-boiling blowing agent by high pressure under the condition that the material temperature is 15-20℃, inject into the premixing tank; S3: mix and foam by high pressure mixing the mixed white material, liquid low-boiling blowing agent and organic polyisocyanate by the high pressure blowing gun head under the condition that the material temperature is 15-20℃, inject into the refrigerator mold preheated to 35-45℃, the pressure of the gun head is 110-160bar, to prepare polyurethane foam.

10. A refrigerator characterized by comprising: The rigid polyurethane thermal insulation material according to any one of claims 4-8.

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