WO2023221693A1

WO2023221693A1 - Rigid polyurethane foam, preparation method, and heat preservation material, refrigerator and freezer comprising polyurethane foam

Info

Publication number: WO2023221693A1
Application number: PCT/CN2023/087779
Authority: WO
Inventors: 胡锋; 曹立军; 刘莉
Original assignee: 海信容声(广东)冰箱有限公司
Priority date: 2022-05-20
Filing date: 2023-04-12
Publication date: 2023-11-23
Also published as: WO2023221693A9; WO2023221694A9; WO2023221694A1

Abstract

Disclosed are a rigid polyurethane foam, a preparation method, and a heat preservation material, refrigerator and freezer comprising a polyurethane foam, relating to the technical field of heat preservation materials, and capable of solving the technical problem that traditional environment-friendly energy-saving polyurethane foaming agents (1-chloro-3,3,3-trifluoropropene, cis-1,1,1,4,4,4-hexafluoro-2-butene) are expensive and have high filling density, resulting in a limited scope of application. A low-density rigid polyurethane foam comprises, in parts by weight, 100 parts of a combined polyether, 16-23 parts of a foaming agent, 1-3 parts of a foaming aid, and 144-160 parts of an organic polyisocyanate, wherein the foaming aid is trifluoropropene. The low-density rigid polyurethane foam has the characteristics of low costs, low foam density, good thermal conductivity coefficient, environmental protection and the like. The present disclosure can be applied to environment-friendly rigid polyurethane foaming agents.

Description

Rigid polyurethane foam, preparation method and insulation material containing polyurethane foam, refrigerator and freezer

Cross-references to related applications

This disclosure claims priority to the Chinese patent application with application number 202210549493.9 filed with the China Patent Office on May 20, 2022; and the priority of the Chinese patent application with application number 202211499386.6 filed with the China Patent Office on November 28, 2022. , the entire contents of which are incorporated into this disclosure by reference.

Technical field

The present disclosure belongs to the field of thermal insulation materials, and in particular relates to a rigid polyurethane foam, a preparation method, thermal insulation materials containing polyurethane foam, refrigerators and freezers.

Background technique

If you want to increase the volume ratio of a refrigerator or freezer, you need to thin the insulation layer of the refrigerator. As an insulation material for refrigerators and freezers, rigid polyurethane foam is one of the key raw materials that directly affects the important performance indicators of refrigerators and freezers. The production efficiency and power consumption of a refrigerator play a decisive role. Rigid polyurethane foam has excellent thermal insulation properties and is widely used in the field of thermal insulation technology. Its environmental protection, thermal conductivity (insulation performance), foam strength, etc. are key indicators for evaluating its performance. At the same time, foam density is a key factor affecting its cost.

Contents of the invention

On the one hand, a rigid polyurethane foam is provided, including in parts by weight: 100 parts of combined polyether, 16 to 23 parts of foaming agent, 1 to 3 parts of foaming assistant, and 144 to 160 parts of organic polyisocyanate; Wherein, the foaming assistant is trifluoropropylene.

The rigid polyurethane foam in some embodiments of the present disclosure is based on the current cyclopentane foaming system (that is, the cyclopentane system and the mixed foaming system with cyclopentane as the main body), and then introduces an appropriate amount of trifluoropropylene as Foaming aid is composed of cyclopentane (or a mixed foaming system with cyclopentane as the main body) + trifluoropropylene mixed foaming system. This foaming agent has the characteristics of low cost, low foam density, and ideal thermal conductivity. .

On the other hand, a method for preparing rigid polyurethane foam is provided, which includes the following steps: according to the proportion of parts by mass, the polyol composition, foam stabilizer, catalyst and water are heated at 25±5°C. Physically mix under temperature conditions and stir for 0.5 to 1.5 hours to obtain the first mixture; uniformly mix the foaming agent, foaming assistant and the first mixture through a static mixer to obtain the second mixture; at 20±3 Under temperature conditions of ℃, the second mixture and the organic polyisocyanate are mixed and foamed in proportion through a high-pressure gun head, and the pressure of the high-pressure gun head is controlled to 110-150 bar to prepare the rigid polyurethane foam.

In another aspect, a thermal insulation material is provided, which is prepared from the rigid polyurethane foam described in any of the above embodiments.

In another aspect, a refrigerator is provided, including the thermal insulation material described in any of the above embodiments.

In another aspect, a freezer is provided, including the thermal insulation material described in any of the above embodiments.

Description of the drawings

Figure 1 is an electron microscope photo of rigid polyurethane foam provided by some embodiments of the present disclosure;

Figure 2 is an electron micrograph of conventional rigid polyurethane foam provided in some comparative examples of the present disclosure.

Detailed ways

The technical solutions in some embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments provided by this disclosure, all other embodiments obtained by those of ordinary skill in the art fall within the scope of protection of this disclosure.

Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and its other forms such as the third person singular "comprises" and the present participle "comprising" are used. Interpreted as open and inclusive, it means "including, but not limited to." In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific "example" or "some examples" and the like are intended to indicate that a particular feature, structure, material or characteristic associated with the embodiment or example is included in at least one embodiment or example of the present disclosure. The schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be included in any suitable manner in any one or more embodiments or examples.

As used herein, "about,""approximately" or "approximately" includes the stated value as well as An average value that is within an acceptable range of deviation for a particular value, as determined by one of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system) determined.

At present, the ideal environmentally friendly foaming agents are alkanes (such as pentane, butane, etc.) and HFOs-like fluoroolefins (such as 1-chloro-3,3,3-trifluoropropene, cis-1,1, 1,4,4,4-hexafluoro-2-butene). Among them, for HFOs-based olefin foaming agents, the currently technically mature ones are 1-chloro-3,3,3-trifluoropropene (HFO-1233zd) and cis-1,1,1,4,4 , 4-hexafluoro-2-butene (HFO-1336mzz), but due to a single supply and exclusive monopoly, product production capacity is limited, resulting in high product prices. Refrigerator and freezer products are labor-intensive industries, and the supply of new foaming agents And high cost has become a major obstacle to the promotion and application in the field of home appliance insulation; and alkanes (such as hydrofluoroalkane low-boiling point foaming agents) have limited practical applications due to their high gas thermal conductivity.

Therefore, developing an environmentally friendly rigid polyurethane foam with controllable cost, low thermal conductivity and low foam density is the current key research and development direction in the field of home appliance polyurethane insulation.

In some embodiments and comparative examples of the present disclosure, polyether polyol A uses sucrose and glycerol as starting agents, with an average functionality of 6.0 and a hydroxyl value of 400 to 480 mgKOH/g; polyether polyol B uses o-toluene di Amine is used as the initiator, with an average functionality of 3.9 and a hydroxyl value of 330-420 mgKOH/g; polyether polyol C uses sorbitol as a initiator, with an average functionality of 4.4 and a hydroxyl value of 400-450 mgKOH/g; Ester polyol is condensed from dicarboxylic acid and ethylene glycol, with an average functionality of 2.8 and a hydroxyl value of 250 to 350 mgKOH/g.

The same types of foam stabilizers, catalysts, and organic polyisocyanates were used in each parallel experiment.

Unless otherwise specified, the reagents, methods and equipment used in this disclosure are conventional reagents, methods and equipment in this technical field. Unless otherwise stated, the reagents and materials used in this disclosure are commercially available.

In some embodiments, a polyurethane foam material is provided, including components in parts by weight as shown in Table 1 and Table 2, and the preparation method includes steps S1 to S4.

In step S1, according to the formula in Table 1, the polyol composition, water, foam stabilizer, and catalyst are mixed at 20 to 30°C to obtain a first mixture.

In step S2, the first mixture and the high-boiling point fluoroolefin blowing agent are mixed in proportion through static premixing equipment at 15-20°C and 1.0-2.5MPa pressure to obtain a second mixture.

In step S3, the second mixture and low-boiling fluoroolefin foaming agent are mixed in proportion through static premixing equipment at 15-20°C and 2.5-4.0MPa pressure to obtain a third mixture, that is, a white material composition .

In step S4, the white material composition and the organic polyisocyanate are mixed and foamed in proportion through a high-pressure foaming gun head, and the pressure of the high-pressure foaming gun head is 110 to 160 bar to prepare the polyurethane foam material.

Table 1 Component contents (parts by weight) of polyurethane foam materials in Examples 1 to 8

Table 2 Component contents (parts by weight) of polyurethane foam materials in Examples 9 to 16

Comparative Examples 1 to 7

Comparative Examples 1 to 7 respectively provide a polyurethane foam material, including components in parts by weight as shown in Table 3, and the preparation method includes steps S11 to S14.

In step S11, according to the formula in Table 3, the polyol composition, water, foam stabilizer, and catalyst are mixed at 20 to 30°C to obtain a first mixture.

In step S12, the first mixture and the high-boiling point fluoroolefin blowing agent are mixed in proportion through static premixing equipment at 15-20°C and 1.0-2.5MPa pressure to obtain a second mixture.

In step S13, the second mixture and low-boiling fluoroolefin foaming agent are mixed in proportion through static premixing equipment at 15-20°C and 2.5-4.0MPa pressure to obtain a third mixture, that is, a white material composition .

In step S14, the white material composition and the organic polyisocyanate are mixed and foamed in proportion through a high-pressure foaming gun head, and the pressure of the high-pressure foaming gun head is 110 to 160 bar to prepare the polyurethane foam material.

Table 3 Component contents (parts by weight) of polyurethane foam materials of Comparative Examples 1 to 7

【Performance Testing】

The polyurethane foam materials obtained in the above examples and comparative examples were tested. The specific test items, test methods and results are as follows:

Molded core density: According to the density test of GB/T 6343-2009 polyurethane foam, test conditions: test by using the drainage method to measure the foam volume, foam density = foam weight/foam volume, sample size (50±1) mm ×(50±1)mm×(50±1)mm, for 1 refrigerator or freezer product Take at least 2 samples from each location.

The density distribution is the difference between the maximum molded core density and the minimum molded core density.

Cell pore size: measured using a Scanning Electron Microscope (SEM).

Thermal conductivity (10°C): Determination of steady-state thermal resistance and related characteristics of thermal insulation materials in accordance with GB/T 10295-2008 heat flow meter method.

Minimum compressive strength (vertical direction): Measured in accordance with GB/T 8813-2008 Compression properties of rigid foam plastics.

Dimensional stability: According to GB/T 8811-2008 Determination of linear dimensions of foam plastics and rubber, the test conditions are -20℃, 48h and -60℃, 48h respectively.

The test results of the examples are shown in Table 4, and the test results of the comparative examples are shown in Table 5.

Test results of the embodiment in Table 4

Table 5 Test results of comparative examples

It should be noted that the amount of low-boiling point fluoroolefin blowing agent in Comparative Example 3* is too much, and it is difficult to mix evenly with other components under conventional processing conditions.

According to the test results in Table 4 and Table 5, the polyurethane foam materials prepared in each embodiment of the present disclosure have appropriate cell sizes, low density, low thermal conductivity, good thermal insulation performance, and excellent resistance to shrinkage and deformation. High dimensional stability at -20°C and -40°C.

From Examples 1 to 8, it can be seen that when the high boiling point fluoroolefin foaming agent is Z-HFO-1336mzz and the low boiling point fluoroolefin foaming agent is HFO-1243zf, the polyurethane foam material has better thermal insulation properties. performance and higher resistance to shrinkage and deformation.

From the test results of Example 1 and Examples 9 to 12, taking into account the thermal insulation performance and shrinkage deformation resistance, it can be seen that the weight ratio of the high boiling point fluoroolefin foaming agent to the low boiling point fluoroolefin foaming agent is ( 12～15):1, the comprehensive performance of polyurethane foam is better.

Comparative Example 1 does not contain a low-boiling point fluoroolefin foaming agent, and the weight ratio of the two foaming agents in Comparative Example 2 exceeds the limited range of this disclosure. It is difficult to produce a polyurethane foam with both thermal insulation performance and shrinkage deformation resistance. Material. The amount of low-boiling point fluoroolefin foaming agent in Comparative Example 3 is too much, and it is difficult to mix evenly with other components under conventional processing conditions.

In Comparative Examples 4 to 7, non-fluorinated olefin foaming agents were used, and the polyurethane foam materials produced had poor cell uniformity, high thermal conductivity, and poor dimensional stability at low temperatures.

Application examples 1 to 4

Both Application Example 1 and Application Example 3 use the polyurethane foam material of Example 1 as the material of the heat insulation layer to prepare a 400L refrigeration and freezing thin-walled refrigerator. The thickness of the foam layer in the foam cavity of the refrigerator is between 20 and 65 mm. The difference between Application Example 1 and Application Example 3 is that the refrigerator in Application Example 3 does not use VIP (Vacuum Insulation Panel) panels.

Both Application Example 2 and Application Example 4 use the polyurethane foam material of Comparative Example 7 as the material of the thermal insulation layer to prepare a 400L refrigeration and freezing thin-walled refrigerator. The thickness of the foam layer in the refrigerator foam cavity is between 20 and 65 mm. The difference between Application Example 2 and Application Example 4 is that the refrigerator in Application Example 4 does not use a VIP board.

The above-mentioned refrigerators were tested for power consumption. The test standards are GB/T8059-2016 household and similar refrigeration appliances and GB 12021.2-2015 household refrigerator power consumption limit values and energy efficiency levels. The test results are shown in Table 6.

Table 6 Test results of application examples

According to the test results in Table 6, it can be seen that the polyurethane foam material of the present disclosure has excellent thermal insulation performance. Using the polyurethane foam material of some embodiments of the present disclosure as the heat insulation layer of the refrigeration and freezing thin-walled refrigerator can reduce or eliminate the need for VIP boards. use.

At the same time, with the improvement of people's living standards and the development of refrigerator technology, the capacity of refrigerators is getting larger and larger. However, high housing prices in cities have limited people's living space. Products with small volume and large volume have become more and more popular. needs, and this needs to be achieved by increasing the floor area ratio. If you want to increase the volume ratio of a refrigerator or freezer, you need to thin the insulation layer of the refrigerator. As an insulation material for refrigerators and freezers, rigid polyurethane foam is one of the key raw materials that directly affects the important performance indicators of refrigerators and freezers. The production efficiency and power consumption of a refrigerator play a decisive role. The insulation layer of the refrigerator is too thin. The thermal insulation performance will decrease. After thinning, in order to achieve the same thermal insulation performance, most refrigerators use vacuum insulation panels (VIP panels), and the cost of VIP is high. Therefore, the price of ultra-thin refrigerator freezers containing VIP panels is usually The price is much higher than that of ordinary refrigerators.

At present, the thickness of the insulation layer of ultra-thin refrigerators and freezers is about 20 to 60mm. With such a thin insulation layer, the wires, tube bundles and other components in the foam cavity of the refrigerator and freezer are distributed in this narrow space. During the polyurethane foam filling process, The flow channel of the foam raw material is narrow and the resistance of the flow channel increases, resulting in insufficient flow of the polyurethane raw material in the cavity. As a result, the distribution of the polyurethane foam is not uniform, and the phenomenon of poor filling is increasing. This not only affects the appearance quality of the refrigerator, but more importantly, This can lead to poor insulation performance of the refrigerator or freezer.

In response to the problem of uneven distribution of polyurethane foam, Chinese patent application CN 115073694A discloses a low-density and ultra-low thermal conductivity rigid polyurethane foam. The foaming system used in this rigid polyurethane foam is LBA foaming agent, butane foaming agent. Foaming agent and methyl formate modifier, by adding butane foaming agent, use its larger saturated vapor pressure to reduce the foam density; by adding methyl formate, the uniformity and fluidity of foam density are improved. However, the storage stability of the foam formed by methyl formate foaming agent is poor, and butane has a high gas thermal conductivity. The use of butane foaming agent will weaken the effect of fluoroolefin on reducing the thermal conductivity, and then The insulation performance of the refrigerator is not good enough.

In addition, because the insulation layer is thinner, the ability of polyurethane foam to resist shrinkage and deformation is particularly important. Polyurethane foam insulation materials made with conventional foam formulas are prone to local shrinkage, affecting the appearance quality of the product.

Therefore, it is necessary to provide a polyurethane foam material with high thermal insulation performance and good resistance to shrinkage and deformation.

Some embodiments of the present disclosure also provide a rigid polyurethane foam, including in parts by weight: 100 parts of combined polyether, 16 to 23 parts of foaming agent, 1 to 3 parts of foaming assistant, and organic polyisocyanate 144 to 160 parts; wherein, the foaming assistant is trifluoropropylene.

In the above embodiment, a rigid polyurethane foam is provided, which is based on the current cyclopentane foaming system (i.e., the cyclopentane system and the mixed foaming system with cyclopentane as the main body), and is introduced An appropriate amount of trifluoropropylene is used as a foaming aid, that is, it forms a cyclopentane (or a mixed foaming system with cyclopentane as the main body) + trifluoropropylene mixed foaming system, which has the characteristics of low cost, low foam density, and ideal thermal conductivity. Features.

It should be noted that the lower the thermal conductivity of the foam, the better the insulation performance and the lower the energy consumption of the resulting product. Since the solid thermal conductivity and foam matrix of polyurethane foam are relatively fixed, its thermal insulation performance is mainly affected by two aspects: (1) The type of foaming agent in the cells. The lower the gas phase thermal conductivity of the foaming agent, the better the thermal insulation performance; ( 2) Cell diameter. The finer the cells, the better the thermal conductivity of the foam.

Based on the above, fluoroolefin has a low gas thermal conductivity and contains multiple fluorine atoms, which can increase the nucleation rate of polyurethane foam during the foaming process. Therefore, the foam has excellent thermal insulation properties. In addition, nucleating additives can also be added, such as 3M's perfluoroolefins (e.g., 5357, Fa-188, 5056, etc.), but these nucleating agents have obvious drawbacks-toxicity or global warming coefficient values (Global Warming Potential, GWP) is high and the cost is high.

Furthermore, the filling density of foam is directly related to the cost of production. The lower the density of foam, the fewer production raw materials used and the lower the cost. Foaming of common fluoroolefins (e.g., 1-chloro-3,3,3-trifluoropropene, cis-1,1,1,4,4,4-hexafluoro-2-butene) can be obtained Foam has good thermal insulation properties, but its density exceeds 30.5kg/m3 and the cost is still high.

It should be noted that adding a low boiling point foaming agent to the foam can reduce the foam density (as low as 27.5~29.0kg/m3) while ensuring the foam strength. Usually, two types of low-boiling point blowing agents are used to add to the foam. One type is alkanes, such as n-butane (boiling point -0.5°C), isobutane (boiling point -11.7°C); the other is hydrofluorocarbons. Foaming agents, such as HFC-134a (boiling point -26.2°C), HFC-152a (boiling point -25.7°C). However, the former has a high gas thermal conductivity, which is not conducive to the thermal insulation performance of the foam after being added; the latter has a high GWP and is a HFCs (Hydrofluorocarbons) substance restricted by various countries' environmental regulations, so its application is gradually increasing. restricted. Based on this, this disclosure compared the performance of five low-boiling point foaming aids including trifluoropropylene and conducted related experiments. Finally, trifluoropropylene was selected as a foaming aid to be added to the current cyclopentane-based foaming aid. in the foaming system.

Furthermore, the main reasons why this disclosure selects trifluoropropylene as a foaming aid are as follows:

1. Excellent environmental performance, its ozone depletion potential (ODP, Ozone Depletion Potential) is 0 and its GWP value is 4.

2. It has the characteristics of low boiling point and high vapor pressure. It is a gas at normal temperature and pressure. It is wrapped in the cells during the foaming process, which can greatly improve the ability of the cells to resist shrinkage and deformation, thereby reducing the foam density.

3. During the foaming process, the fluidity of the foam can be improved, the density distribution of the foam can be improved, and the quality of the product can be improved.

4. As a low boiling point substance, the polyfluorine atomic structure also has nucleation properties, making the prepared foam more fine and uniform, and can improve the thermal conductivity of the foam.

In addition, the organic polyisocyanate can specifically be selected from one or a mixture of PM2010 and PM200 of Yantai Wanhua Company, 44V20L of Covestro Company, M20s of BASF Company, Suprasec 5005 of Huntsman Company, and PAPI27 of DOW Company, preferably PM2010 .

In some embodiments, the combined polyether includes at least a polyol composition, a foam stabilizer, a catalyst, and water.

In some embodiments, the polyol composition is a polyether monomer selected from the group consisting of amine ethers, glyceryl polyethers, sucrose polyethers, mannitol polyethers, sorbitol polyethers, glyceryl sucrose polyethers, xylene polyethers Or at least one of polyester and polyether; the foam stabilizer is an organosilicon compound; the catalyst is a composite catalyst of tertiary amines and organotin.

In the above embodiment, the foam stabilizer is an organic silicon compound or an organic silicon compound, and its main structure is: polysiloxane-alkylene oxide block copolymer. Specifically, B8460, B8461, and B8462 of Evonik Degussa can be selected. , B8465, B8471, B8474, B8476, B8481, etc.; AK8805, AK8815, AK8812, AK8809, etc. of Meside Company; one or several mixtures of L6900, L6863, etc. of Momentive Company; the catalyst is a tertiary amine and an organic The tin composite catalyst can be selected from any one or combination of TMR-2, PC-5 (or A-1), and PC-8.

In some embodiments, the foaming agent includes pentane, with a weight ratio of 11 to 17, preferably 13 to 16, and the pentane is cyclopentane or cyclopentane and isopentane in a mass ratio of (7 to 9 ): (3～1) A mixture composed of.

In the above embodiment, the weight parts of pentane can be specifically selected from 11, 12, 13, 14, 15, 16, 17, or any value within the above limited range can be selected according to actual needs, all of which fall within the protection scope of the present disclosure. Inside.

In some embodiments, the blowing agent also includes 1-chloro-3,3,3-trifluoropropene (HFO-1233zd) or cis-1,1,1,4,4,4-hexafluoro-2- At least one kind of butene (HFO-1336mzz) has a weight portion of 0 to 10, preferably 0 to 8.

In the above embodiment, 1-chloro-3,3,3-trifluoropropene (HFO-1233zd) or cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO- The weight parts of 1336mzz) can be specifically selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 according to actual needs. Any value within the above limited range falls within the protection scope of the present disclosure. within.

The present disclosure also provides a method for preparing rigid polyurethane foam, including step S21 to step S23.

In step S21, physically mix the polyol composition, foam stabilizer, catalyst and water at a temperature of 25±5°C according to the proportion by mass, and stir for 0.5 to 1.5 hours to obtain the first mixture;

In step S22, the foaming agent, foaming assistant and the first mixture are uniformly mixed through a static mixer to obtain a second mixture;

In step S23, under the temperature condition of 20±3°C, the second mixture and the organic polyisocyanate are mixed and foamed in proportion through a high-pressure gun head, and the pressure of the gun head is controlled to 110-150 bar to prepare rigid polyurethane foam.

In order to introduce the rigid polyurethane foam, the preparation method and the insulation material, refrigerator or freezer containing polyurethane foam provided by some embodiments of the present disclosure more clearly and in detail, the following will be described in conjunction with specific embodiments.

【Foaming additive low boiling point substance screening experiment】

In order to obtain the most suitable low-boiling point foaming aid for rigid polyurethane foaming agents, this disclosure comprehensively compared five substances including trifluoropropylene, and finally selected trifluoropropylene as the most suitable foaming aid. , the specific screening process is as follows:

Table 7 Performance comparison of low boiling point substances

As can be seen from the table, although HFC-134a and HFC-152a have lower boiling points and higher vapor pressures, their global warming coefficient values are relatively high, and they belong to HFCs and are subject to increasingly stringent domestic regulations. Restricted by external environmental protection regulations; butane is environmentally friendly, but the gas thermal conductivity is relatively high, so the thermal insulation performance of the prepared polyurethane foam cannot achieve optimal results; while trifluoropropylene has a low boiling point, high vapor pressure, and is environmentally friendly It has good thermal conductivity, low gas thermal conductivity, and the polyfluorine atom-containing structure has nucleation properties, which can further improve the thermal insulation effect of the foam. Therefore, it is an ideal low-boiling point foaming aid.

Comparative example 8

This comparative example provides rigid polyurethane foam and its preparation method, specifically:

Rigid polyurethane foam, in parts by weight, includes the following components:

100 parts of polyol composition, 2.1 parts of foam catalyst, 2.2 parts of foam stabilizer, 1.9 parts of water, 16 parts of foaming agent-pentane, and 147 parts of organic polyisocyanate.

The preparation method of rigid polyurethane foam includes the following steps:

(1) Physically mix the polyol composition, foam stabilizer, foam catalyst and water according to the proportion by mass at a temperature of 25±5°C, and stir for 0.5 to 1.5 hours to obtain the first mixture;

(2) Evenly mix the foaming agent and the first mixture through a static mixer to obtain a second mixture;

(3) Under the temperature condition of 20±3°C, mix the second mixture and the organic polyisocyanate in proportion through a high-pressure gun head to foam, and control the pressure of the gun head to 110-150 bar to prepare rigid polyurethane foam.

Comparative example 9

Rigid polyurethane foam, in parts by weight, includes the following components:

100 parts of polyol composition, 2.1 parts of foam catalyst, 2.2 parts of foam stabilizer, 2.1 parts of water, 12.5 parts of foaming agent-pentane, and 151 parts of organic polyisocyanate.

The preparation method of rigid polyurethane foam is the same as that of Comparative Example 8. The difference is that in this comparative example, rigid polyurethane foam is prepared according to the above formula.

Comparative example 10

Rigid polyurethane foam, in parts by weight, includes the following components:

100 parts of polyol composition, 2.1 parts of foam catalyst, 2.2 parts of foam stabilizer, 2.2 parts of water, 12.5 parts of foaming agent-pentane, 7 parts of foaming agent-HFO-1336mzz, 2 parts of foaming agent-n-butane parts, 153 parts of organic polyisocyanates.

Comparative example 11

Rigid polyurethane foam, in parts by weight, includes the following components:

100 parts of polyol composition, 2.1 parts of foam catalyst, 2.2 parts of foam stabilizer, 2.2 parts of water, 12.5 parts of foaming agent-pentane, 7 parts of foaming agent-HFO-1336mzz, and 151 parts of organic polyisocyanate.

Example 17

This embodiment provides rigid polyurethane foam and its preparation method, specifically:

Rigid polyurethane foam, in parts by weight, includes the following components:

100 parts of polyol composition, 2.1 parts of foam catalyst, 2.2 parts of foam stabilizer, 1.9 parts of water, 16 parts of foaming agent - pentane, 3.0 parts of foaming assistant - trifluoropropylene, and 150 parts of organic polyisocyanate.

The preparation method of rigid polyurethane foam includes the following steps:

(2) Evenly mix the foaming agent, foaming assistant and the first mixture through a static mixer to obtain the second mixture;

(3) Under the temperature condition of 20±3°C, use a high-pressure gun tip to mix the second mixture and the organic polyisocyanate in proportion to foam, and control the gun tip pressure to 110-150 bar to prepare rigid polyurethane foam.

Example 18

Rigid polyurethane foam, in parts by weight, includes the following components:

100 parts of polyol composition, 2.1 parts of foam catalyst, 2.2 parts of foam stabilizer, 2.1 parts of water, 13.5 parts of foaming agent-pentane, 7 parts of foaming agent-HFO-1233zd, 2.0 parts of trifluoropropylene, organic polypropylene 155 parts of isocyanate.

The preparation method of rigid polyurethane foam is the same as in Example 17, except that in this embodiment, rigid polyurethane foam is prepared according to the above formula.

Example 19

Rigid polyurethane foam, in parts by weight, includes the following components:

100 parts of polyol composition, 2.1 parts of foam catalyst, 2.2 parts of foam stabilizer, 2.2 parts of water, 13.5 parts of foaming agent - pentane, 7 parts of foaming agent - HFO-1336mzz, foaming assistant - trifluoropropylene 2.0 parts, 155 parts of organic polyisocyanate.

【Performance Testing】

This disclosure has conducted multiple performance tests on the rigid polyurethane foams prepared in the above comparative examples and examples, including free foam density, average thermal conductivity (10°C, 0°C), average compressive strength, and dimensional stability. Specific tests The results are shown in the table below:

Table 8 Raw material ratios and foam properties of Examples and Comparative Examples

It can be seen from the data in Table 8 that compared with the comparative example, the rigid polyurethane foam prepared using the formula and preparation method provided by the present disclosure has smaller thermal conductivity, better thermal insulation performance, lower dimensional deformation rate, and better foam mechanical properties. good. After the molded core density of the foam is greatly reduced, the compressive strength of the foam is similar and the overall performance is excellent. It can be seen that the density of the rigid polyurethane foam core provided by the present disclosure can be as low as about 26.76kg/m3, which can reduce the amount of raw material injection while still maintaining good overall performance and meeting the needs of refrigerator manufacturers. It can be seen that under the same process parameters, the polyurethane foam prepared using the foam composition formula provided by the present disclosure can effectively reduce the amount of raw material injection and reduce the foam density, thereby achieving the purpose of reducing production costs. Note: The performance test standards in Table 8 are as follows:

Free foam density, molded core density: GB/T 6343-95 Density test of polyurethane foam.

Compressive strength: GB/T 8813-2008 Determination of compression properties of rigid foam plastics.

Thermal conductivity: GB/T 10295-2008 Determination of steady-state thermal resistance and related characteristics of thermal insulation materials using heat flow meter method.

Dimensional stability: GB/T 8811-2008 Determination of linear dimensions of foam plastics and rubber.

[Energy consumption test of rigid polyurethane foam on a 300L refrigeration and freezer product]

This disclosure further conducted a complete machine energy consumption test on the rigid polyurethane foam obtained in Example 17 and Comparative Example 8 on a 300L refrigeration and freezer product. The measurement results are shown in Table 9.

Table 9 Machine energy consumption test data

The above whole machine performance tests were conducted in accordance with Chinese standards (GB/T8059-2016 Household and similar refrigeration appliances and GB 12021.2-2015 Household refrigerator power consumption limit values and energy efficiency levels), by It can be seen from the table data that compared with Comparative Example 8, the energy consumption of the refrigerator product using some embodiments of the present disclosure is reduced by 3.24%, and the load temperature rise time is increased by 16.39%. At the same time, the present disclosure also took electron microscopy photos of the polyurethane foams of Example 17 and Comparative Example 8 (as shown in Figures 1 to 2). From the figures, it can be seen that the rigid polyurethane foam prepared by the present disclosure is more dense, and The cells are smaller and more uniform.

Based on the results in Tables 8 and 9 and Figure 2, this disclosure can make the cells finer and better solve the problem by introducing trifluoropropylene with good environmental protection and compounding it with the currently commonly used foaming system. The defect of high thermal conductivity when cyclopentane is used alone reduces the density and thermal conductivity of polyurethane rigid foam. At the same time, it can solve the problem that butane low boiling point foaming systems cannot improve the thermal conductivity of foams such as HFC-134a and HFC-152a. The low boiling point foaming system has a high GWP value and is not environmentally friendly. The method of preparing rigid polyurethane foam using the composition described in the present disclosure is particularly suitable for refrigerator and freezer products, and can better achieve environmental protection, energy saving and resource conservation of refrigerator and freezer products.

The present disclosure also provides a thermal insulation material prepared by using the low-density rigid polyurethane foam as described in any of the above embodiments.

The present disclosure also provides a refrigerator, which includes an insulation material prepared from the above-mentioned low-density rigid polyurethane foam.

The present disclosure also provides a freezer, which includes an insulation material prepared from the above-mentioned low-density rigid polyurethane foam.

It should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure and do not limit the scope of protection of the present disclosure. Although the present disclosure has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art will understand that the present disclosure can be modified. The disclosed technical solution may be modified or equivalently substituted without departing from the essence and scope of the disclosed technical solution.

In the description of the present disclosure, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", " The orientation or positional relationship indicated by "outer", "middle", "vertical", "horizontal", "horizontal", "vertical", "X-axis direction", "Y-axis direction", "Z-axis direction", etc. is based on The orientation or positional relationship shown in the drawings is only to facilitate the description of the present disclosure and simplify the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as Limitations on the Disclosure. And, on In addition to being used to express orientation or positional relationships, some of the terms mentioned above may also be used to express other meanings. For example, the term "on" may also be used to express a certain dependence or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this disclosure can be understood according to specific circumstances.

The above are only preferred embodiments of the present disclosure. It should be noted that those of ordinary skill in the art can also make several improvements and substitutions without departing from the technical principles of the present disclosure. These improvements and substitutions It should also be regarded as the protection scope of this disclosure.

Claims

Rigid polyurethane foam, in parts by weight, includes: 100 parts of combined polyether, 16 to 23 parts of foaming agent, 1 to 3 parts of foaming assistant, and 144 to 160 parts of organic polyisocyanate; wherein, the foaming The additive is trifluoropropylene.
The rigid polyurethane foam according to claim 1, wherein the combined polyether includes at least a polyol composition, a foam stabilizer, a catalyst and water.
The rigid polyurethane foam according to claim 2, wherein the polyol composition is a polyether monomer selected from the group consisting of amine ether, glycerol polyether, sucrose polyether, mannitol polyether, sorbitol polyether, At least one of glycerol sucrose polyether, xylene polyether or polyester polyether; the foam stabilizer is an organosilicon compound; the catalyst is a composite catalyst of tertiary amines and organotin.
The rigid polyurethane foam according to any one of claims 1 to 3, wherein the foaming agent includes pentane, with a weight portion of 11 to 17, and the pentane is cyclopentane or cyclopentane. A mixture composed of isopentane and isopentane in a mass ratio of (7~9): (3~1).
The rigid polyurethane foam according to claim 4, wherein the weight portion of the pentane is 13 to 16.
The rigid polyurethane foam according to claim 4, wherein the foaming agent further includes 1-chloro-3,3,3-trifluoropropene or cis-1,1,1,4,4,4- At least one kind of hexafluoro-2-butene has a weight portion of 0 to 10.
The rigid polyurethane foam according to any one of claims 1 to 6, wherein the foaming agent further includes 1-chloro-3,3,3-trifluoropropene or cis-1,1,1, At least one kind of 4,4,4-hexafluoro-2-butene has a weight portion of 0 to 8.
The preparation method of rigid polyurethane foam according to any one of claims 1 to 7, comprising the following steps:

According to the proportion by mass, the polyol composition, foam stabilizer, catalyst and water are physically mixed at a temperature of 25±5°C, and stirred for 0.5 to 1.5 hours to obtain the first mixture;

The foaming agent, foaming assistant and the first mixture are uniformly mixed through a static mixer to obtain a second mixture;

Under the temperature condition of 20±3°C, the second mixture and the organic polyisocyanate are mixed and foamed in proportion through a high-pressure gun head, and the pressure of the high-pressure gun head is controlled to 110-150 bar to obtain the hard Quality polyurethane foam.
Thermal insulation material is prepared from the rigid polyurethane foam according to any one of claims 1 to 7.
A refrigerator including the thermal insulation material according to claim 9.
Freezer, including the thermal insulation material as claimed in claim 9.