CN112920448B - Premixing method of isocyanate and method for rapidly filling foaming stock solution into mold cavity - Google Patents
Premixing method of isocyanate and method for rapidly filling foaming stock solution into mold cavity Download PDFInfo
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- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
- C08J9/12—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent
- C08J9/14—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent organic
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- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/40—High-molecular-weight compounds
- C08G18/4009—Two or more macromolecular compounds not provided for in one single group of groups C08G18/42 - C08G18/64
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- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/40—High-molecular-weight compounds
- C08G18/4009—Two or more macromolecular compounds not provided for in one single group of groups C08G18/42 - C08G18/64
- C08G18/4018—Mixtures of compounds of group C08G18/42 with compounds of group C08G18/48
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- C08G18/00—Polymeric products of isocyanates or isothiocyanates
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- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/40—High-molecular-weight compounds
- C08G18/42—Polycondensates having carboxylic or carbonic ester groups in the main chain
- C08G18/4236—Polycondensates having carboxylic or carbonic ester groups in the main chain containing only aliphatic groups
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- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/40—High-molecular-weight compounds
- C08G18/48—Polyethers
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- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
- C08J9/12—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent
- C08J9/14—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent organic
- C08J9/143—Halogen containing compounds
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Abstract
The application discloses a premixing method of isocyanate, which comprises the following steps: raw material preparation: isocyanate with insoluble matter content less than or equal to 0.02wt%; the moisture is less than 0.005wt% of inert compound A; (2) mixing: the isocyanate and the inert compound a are introduced into a static mixer and mixed to obtain a premix B. Secondly, the application also provides a method for rapidly filling the foaming stock solution into the die cavity. The method can prevent the isocyanate activity from being reduced or from being invalid and deteriorated, avoid introducing impurities into the premix and ensure that the premixing process is carried out smoothly. The obtained premix B can realize the regulation and control of the flow rate of the polyurethane foaming stock solution, and has low viscosity and good fluidity. The premix B and the rapid filling method can be suitable for moulds with complex cavity structures, and have the advantages of high filling speed and demoulding speed, and can improve the product quality, the product qualification rate and the production efficiency.
Description
Technical Field
The invention belongs to the field of organic high molecular compounds, and particularly relates to a premixing method of isocyanate and a method for rapidly filling a foaming stock solution into a mold cavity.
Background
Isocyanate is one of important raw materials of polyurethane foam, and a method for directly mixing and foaming combined polyether and isocyanate is generally adopted in industry to prepare the polyurethane foam, and the foaming method has the characteristics of simplicity in operation and convenience in use. However, with the development of the blowing agent substitution technology, the diversification of the foaming system and the transformation of the demands of clients, the conventional foaming manner cannot meet the demands of the existing high-efficiency and high-quality production, so that researchers propose some improvements on the conventional foaming method, for example, CN108976463a discloses a technical scheme of premixing the blowing agent with isocyanate and then mixing and foaming with the polyol system, which can meet the use demands of the high-viscosity polyether polyol and can widen the selection range of the blowing agent.
Although the prior art discloses the technical concept of premixing the foaming agent and isocyanate, no specific premixing method, quality control in the premixing process and other technologies are mentioned, and these are key factors influencing the premixing effect. As can be seen from the chemical characteristics of isocyanate, isocyanate is a compound with extremely high reactivity, is extremely sensitive to water, and can generate insoluble urea compounds, emit carbon dioxide and cause viscosity increase after being contacted with moisture in air; in addition, isocyanate undergoes self-polymerization to form insoluble substances such as dimers, and the viscosity increases. The negative effects of the above phenomena are manifold: (1) The impurities in the mixing process consume part of isocyanate, so that the effective quality of the isocyanate is reduced; (2) The viscosity of the isocyanate component is increased, which is not beneficial to the full mixing of the isocyanate and the reaction raw materials, thereby affecting the polyurethane reaction process; (3) Insoluble materials can adversely affect the foam formation process. At the same time, isocyanate acts as a volatile toxic substance which can also cause irritation and injury to the human body during use. Therefore, for the premixing operation of isocyanate, not only reasonable scheme design is needed to ensure the effective quality of isocyanate and the personal safety of operators, but also corresponding solutions are needed to solve the problems of failure and deterioration of isocyanate, impurity introduction and the like in the premixing process.
Disclosure of Invention
The object of the present invention is to at least partially solve one of the following problems: (1) The viscosity of isocyanate is increased, the activity is reduced or the isocyanate becomes invalid and deteriorated during or after premixing; (2) the premixing process is difficult to control; (3) After the isocyanate, the polyol and the like form foaming stock solution, the filling effect in a die cavity is poor, and various properties of the obtained polyurethane foam are difficult to be simultaneously considered.
To achieve the above object, the present invention provides a method for premixing isocyanate, i.e. a method for uniformly mixing isocyanate with another substance, wherein the premixing method comprises mixing liquid isocyanate with an inert compound A through a static mixer, wherein the inert compound A is an inert liquid foaming agent and/or an inert gaseous foaming agent, and the method specifically comprises the following steps: raw material preparation:
isocyanate, the content of insoluble matters in the isocyanate is less than or equal to 0.02wt%;
an inert compound A, the moisture of the inert compound A being < 0.005wt%;
the inert compound A is an inert liquid foaming agent and/or an inert gaseous foaming agent;
(2) Mixing: the isocyanate and the inert compound a are introduced into a static mixer and, after mixing, a premix B is obtained.
The inert material in the invention is inert and does not react with isocyanate or deteriorate isocyanate, the liquid state is liquid state under the environment of 20 ℃ and 101KPa, and the gas state is gas state under the environment of 20 ℃ and 101 KPa. The main component of the inert compound a is inert, but it is inevitable to introduce some non-inert substances such as water in the air during the production, storage and transportation thereof. Therefore, in order to prevent the isocyanate from reacting with water, it is necessary to control the moisture of the inert compound a so as to reduce the moisture to a certain range. Experiments show that the water content is controlled to be less than 0.005%, the isocyanate failure can be prevented, the smooth premixing process is ensured, insoluble substances are not generated in the premix B, and the raw materials and energy sources can be saved. Meanwhile, experiments show that the water content is less than 0.005%, which is favorable for improving the compatibility between the inert compound A and isocyanate and further promoting the flow of polyurethane foaming stock solution. The moisture removal of the inert compound a may be performed by a dry nitrogen substitution method, a dry filter method, or the like.
Since the isocyanate is very reactive in chemical properties, it also generates insoluble substances during storage and increases the viscosity of the isocyanate, and experiments have found that when the content of insoluble substances exceeds a certain range, the formation of uniform fine cells is hindered, eventually leading to deterioration of the physicochemical properties of the polyurethane foam. When the content of insoluble matters is controlled within the range of less than or equal to 0.02%, the negative effects can be effectively avoided, and the effective quality of isocyanate and the excellent performance of polyurethane foam are further ensured.
The invention uses static mixer to pre-mix, which can prevent bubble generation in the pre-mix, and can realize good dispersion and full mixing between isocyanate and inert compound A. The static mixer used in the invention can be of an SX type (namely, the units of the static mixer are formed into a plurality of X-shaped units by crossed cross bars according to a certain rule), an SV type (namely, the units of the static mixer are formed into a cylinder by assembling corrugated plates with a certain specification), an SK type (namely, the units of the static mixer are formed by assembling and welding spiral slices twisted left and right of a single pore canal), an SH type (namely, the units of the static mixer are formed by assembling and welding spiral slices of double pore canals, the positions of the double pore canals of adjacent units are staggered by 90 degrees, and a fluid distribution chamber is arranged between the units) or an SL type (namely, the units of the static mixer are formed into a plurality of L-shaped units by the crossed cross bars according to a certain rule).
In summary, through the control of the moisture and the insoluble content, the generation of invalid and invalid samples can be avoided, the premixing process is convenient to control, meanwhile, the viscosity of the premix B obtained by the premixing method is lower, the compatibility among materials is good, the fluidity of polyurethane foaming stock solution is improved, the filling effect is improved, the uniform mixing and full reaction of polyurethane raw materials are facilitated, uniform and fine foam holes are formed, and the comprehensive performance of the foam is improved. And the static mixer is sealed in a mixing environment, so that the irritation or damage to human bodies caused by volatilization of isocyanate can be prevented.
Preferably, the relative humidity in the cavity of the static mixer is less than or equal to 10% before the raw materials enter.
In order to obtain better mixing effect, besides controlling the quality of raw materials, the static mixer is ensured to be clean and dry, wherein the cleaning refers to no pollutant in the static mixer, and the drying refers to the relative humidity in the cavity of the static mixer is less than or equal to 10 percent. The limitation of the relative humidity is beneficial to improving the premixing effect, avoiding the reduction of the isocyanate activity or the invalidation deterioration, facilitating the quality control of the premixing process, and simultaneously avoiding the problem of energy waste caused by drying the static mixer without targets. For the control of the relative humidity in the inner cavity of the static mixer, the mixer can be dried by adopting a hot drying method, a dry air drying method, a dry nitrogen drying method and the like.
Preferably, the weight ratio of the inert compound a to the isocyanate is 1: 7-20. The proportion can better realize the mixing of the inert compound A and isocyanate, if the inert compound A is too much, the inert compound A is easy to separate from the isocyanate, so that the raw material loss is caused, if the inert compound A is too little, the viscosity of the isocyanate and the fluidity of the polyurethane foaming stock solution can not be obviously improved, and experiments show that the mixing proportion is controlled in the above range, so that the compatibility of the inert compound A and the isocyanate is good, the stability of the premix B is improved, and the flow of the polyurethane foaming stock solution is facilitated.
Preferably, a temperature control system is arranged outside the static mixer, and the temperature of raw materials in the static mixer is controlled to be 5-22 ℃. The temperature control system is additionally arranged outside the static mixer, so that the temperature of the mixed system can be controlled. Experiments show that in the mixing process of materials, the temperature of the materials is controlled to be 5-22 ℃, so that the gaseous escape of the foaming agent can be reduced, the compatibility between the materials is improved, the materials are in an optimal flowing state, and meanwhile, the materials can be directly used for production after being mixed, so that the process of re-temperature adjustment treatment is omitted, the process flow is simplified, the energy is saved, and the use is convenient. The temperature control system may specifically be: a jacket is arranged outside the static mixer, and cooling water or steam is introduced into the jacket to adjust the temperature in the static mixer.
Preferably, the technical scheme further comprises on-line detection of moisture of the inert compound A. The on-line detection of the invention, namely, the detection equipment is connected with the production line, and the on-line detection and the real-time feedback are carried out by utilizing the software measurement technology. The process can better guide production, improve production efficiency and facilitate quality control and production serialization. The method for detecting the moisture in the invention can be carried out by adopting a Karl Fischer method or a gas chromatography method.
The water content of the inert compound A is detected on line, so that the continuity of raw material detection can be realized, the quality of the inert compound A can be controlled continuously, and the continuity of the mixing process can be realized. Meanwhile, the change of the water can be monitored in real time according to the data obtained by the online detection of the water, and the bad hidden trouble caused by the exceeding of the water quantity can be eliminated in time.
Specifically, the viscosity of the premix B at 5℃is < 800 mPas. Further, the viscosity of the premix B at 5℃is controlled to 560 to 780 mPas.
Because the viscosity of the premix B is low, the compatibility among materials is good, the polyurethane foaming stock solution has good fluidity, a uniform and fine cell structure is formed conveniently, various performances of the foam are considered, and the filling requirements of cavities with various complex structures are met. The adjustment of the viscosity can be achieved in particular by adjusting the specific components and proportions of the inert compound a.
Preferably, the isocyanate is at least one of polymethylene polyphenyl isocyanate, toluene diisocyanate or modified isocyanate. The isocyanate of the type is beneficial to regulating and controlling the fluidity, the reaction speed and the like of the polyurethane foaming raw liquid, is easy to obtain and has convenience. Wherein the modified isocyanate is polymethylene polyphenyl isocyanate or toluene diisocyanate modified by polyether polyol, bio-based polyol, carbon dioxide-based polyol or polyester polyol. Namely, polymethylene polyphenyl isocyanates modified with polyether polyols, bio-based polyols, carbon dioxide-based polyols or polyester polyols, and toluene diisocyanates modified with polyether polyols, bio-based polyols, carbon dioxide-based polyols or polyester polyols. Among them, polyether polyols, bio-based polyols, carbon dioxide-based polyols and polyester polyols are polyols commonly used in the industry.
Preferred are glycerol polyether modified polymethylene polyphenyl isocyanate, ethylene glycol adipate polyester modified toluene diisocyanate, propylene glycol polyether modified polymethylene polyphenyl isocyanate, phthalic anhydride polyester modified polymethylene polyphenyl isocyanate, bio-based polyol modified toluene diisocyanate, and carbon dioxide based polyol modified toluene diisocyanate. The modified isocyanate can improve the compatibility of foam materials, regulate and control the fluidity and the reaction speed of polyurethane foaming stock solution, and meet the filling requirements of cavities with various complex structures.
Preferably, the inert liquid blowing agent may be selected from n-pentane (NP), isopentane (IP), cyclopentane (CP), 1,3, at least one of pentafluorobutane (HFC-365 mfc), cis-1, 4-hexafluoro-2-butene (FEA-1100, HFO-1336 MZZ) and 1-chloro-3, 3-trifluoropropene (HFO-1233 zd).
Preferably, the method comprises the steps of, the inert gaseous blowing agent may be selected from the group consisting of n-butane, isobutane, 1, 3-tetrafluoropropene (HFO-1234 ze) 2, 3-tetrafluoropropene (HFO-1234 yf), 1, 2-tetrafluoroethane (HFC-134 a), 1-difluoroethane (HFC-152 a), and 1,3, one or more of pentafluoropropane (HFC-245 fa) and hexafluoropropylene.
The preferable inert liquid foaming agent or inert gaseous foaming agent is beneficial to regulating and controlling the fluidity of the polyurethane foaming stock solution, so that the fluidity of the foaming stock solution can meet the cavity filling requirements of various complex structures.
Secondly, the application also provides a method for rapidly filling the foaming stock solution into the die cavity, which is characterized by comprising the following steps:
(1) Premixing liquid isocyanate and an inert compound A by using the premixing method of any isocyanate to obtain a premix B, wherein the viscosity of the premix B at 5 ℃ is less than 800 mPa.s;
(2) Regulating the temperature of the premix B to be 5-22 ℃ and regulating the temperature of the combined polyether to be 12-32 ℃;
(3) Premix B is mixed with the combined polyether to form a foaming stock solution, the foaming stock solution is injected into the mold cavity at a set pressure, and the set pressure is maintained up to the solidification of the foam.
The viscosity of the polyurethane foam stock, i.e. the reactant after mixing the polyether composition with the isocyanate premix, gradually increases during the filling of the mold cavity, and thus the flow rate gradually decreases, and when the fiber time is reached, the foam is substantially free of flowability. By adopting the rapid filling method, the flow of polyurethane foaming stock solution can be regulated and controlled by controlling the viscosity and the material temperature, so that the rapid filling method can be suitable for an appliance with a complex cavity structure, has high filling speed and high demolding speed, and can improve the product quality, the product qualification rate and the production efficiency.
Further, the foaming stock solution consists of the following components in parts by weight:
81-139 parts of combined polyether
133-198 parts of premix B
Wherein the combination polyether comprises:
the foaming stock solution formed by the components can be well matched with the premixing method of isocyanate, so that the effects of rapid filling (the fiber time is less than or equal to 70 seconds) and rapid demolding (the curing time is less than or equal to 100 seconds) are realized, and the production efficiency can be effectively improved.
By the method for quickly filling the mold cavity, the polyurethane foaming stock solution can quickly fill the mold cavity and form the polyurethane rigid foam material, and the heat conductivity coefficient of the foam material is less than or equal to 19 mW/(m.K) @10 ℃, and the density is less than or equal to 27kg/cm 3 The better foam performance is ensured under the condition of (1), the production efficiency is improved, and the production cost is saved.
Specifically, the curing time is less than 100 seconds, and more preferably, the curing time is not less than 50 seconds. Thus, the production efficiency can be effectively improved.
The invention has the following beneficial effects:
(1) Through the detection and treatment processes, the reduction of the isocyanate activity or the invalidation and deterioration of the isocyanate can be prevented, the introduction of impurities into the premix is avoided, and the smooth proceeding of the premix process is ensured;
(2) The premixing process can be detected and fed back in real time through online detection, so that the production is guided better, the production efficiency is improved, and the quality control and the production continuity are facilitated;
(3) The obtained premix B can realize the regulation and control of the flow speed of the polyurethane foaming stock solution, has low viscosity and good fluidity, and can meet the filling requirements of cavities with various structures, in particular to the filling of complex cavity structures;
(4) The obtained premix B and the rapid filling method can be suitable for moulds with complex cavity structures, and have the advantages of high filling speed, high demoulding speed and capability of improving the product quality, the product qualification rate and the production efficiency.
Detailed Description
For a better understanding of the present application, the content of the present application is further elucidated below in conjunction with the examples, but the content of the present application is not limited to the following examples only.
In the present invention, various terms in the present invention are defined as follows, unless otherwise specified:
apparent core density: injecting polyurethane foaming stock solution into a mould to prepare foam with average core density;
fiber time: the time from the beginning of the mixing of the raw materials to the time that a fine rod can just pull out the fine fiber-shaped filaments from the polyurethane foaming stock solution;
curing time: and (3) injecting the polyurethane foaming stock solution into a mould until the polyurethane foaming stock solution is cured and completely molded.
Filling performance: observing whether the mold cavity is fully filled, and if all the spaces in the mold are fully filled, obtaining complete filling; otherwise, it is called underfill.
Mixing effect: the premix B was checked for appearance, and if the appearance was clear liquid and no mechanical impurities were visible, the mixing effect was considered good, and if the appearance was cloudy, the mixing effect was considered poor.
The method for detecting the content of insoluble matters in the invention is carried out by referring to indexes about the content of insoluble matters in GB/T13941-2015 diphenylmethane diisocyanate and methods of annex B or annex C; the method for detecting the moisture is carried out by referring to GB/T7376-2008 industrial fluorine alkane trace moisture determination; the apparent core density and the heat conductivity coefficient are carried out according to the method in GB/T26689-2011 hard polyurethane foam plastics for refrigerator and freezer.
Preparation of an isocyanate premix:
and replacing air in the static mixer by using dry high-purity nitrogen until the relative humidity in the cavity of the static mixer is less than or equal to 10%. The raw materials in table 1 were premixed as follows.
(1) Detecting and processing raw materials: detecting the content of insoluble substances in isocyanate, selecting isocyanate with the content of insoluble substances less than or equal to 0.02%, detecting the moisture of the inert compound A, removing the moisture when the moisture of the inert compound A is more than or equal to 0.005%, and reducing the moisture of the inert compound A to less than 0.005%; (2) mixing: the isocyanate and the inert compound a are introduced into a static mixer and, after mixing, a premix B is obtained.
TABLE 1 premix ingredients
The mixing ratio in table 1 is the weight ratio of inert compound a to isocyanate, wherein inert compound a comprises the total amount of inert liquid blowing agent and inert gaseous blowing agent.
After the premixing operation, premixes B-1# to B-9# were obtained, and the analysis, treatment and performance characterization of the relevant raw materials are shown in Table 2. Wherein, the premix of B-1# to B-4# is detected in an on-line manner, the used instrument is a Swiss Wantong 875KF gas moisture detector, the moisture change can be observed in real time, the method is simple and convenient, and the labor and time cost are saved.
For the B-5# to B-9# premixes, a temperature control system is additionally arranged outside the static mixer, the temperature control system is a jacket arranged outside the static mixer, and hot steam or condensed water is introduced into the jacket according to the temperature requirements in Table 2. The premix B-5# to B-9# can be directly used for polyurethane reaction without temperature adjustment treatment again, thereby saving time and energy.
Table 2 test results and performance characterizations
As can be seen from Table 2, premix B was clear in appearance after the moisture removal treatment, free of impurities, and became cloudy during the mixing process without the moisture removal. Experiments have found that when the insoluble content exceeds 0.02%, turbidity occurs and the viscosity of the premix increases, affecting the mixing effect and the later use.
Preparation of the combined polyether:
preparation of the combined polyether was performed according to the raw materials in table 3.
Table 3 Combined polyether raw materials
Quick filling of polyurethane foaming stock solution:
the following procedure was followed with the corresponding reaction conditions shown in Table 4.
(1) According to the method for preparing an isocyanate premix, the isocyanate and the inert compound A are premixed to obtain a premix B, wherein the viscosity of the premix B at 5 ℃ is less than 800 mPa.s.
(2) The temperature of the isocyanate premix B is controlled to be 5-22 ℃ and the temperature of the combined polyether is controlled to be 12-32 ℃.
(3) And mixing the premix B with the combined polyether to form a foaming stock solution, and injecting the foaming stock solution into a die cavity under normal pressure until the foam is solidified to obtain the polyurethane foam.
TABLE 4 fast filling raw materials and reaction conditions
Comparative examples 6 to 8 were comparative-1 # premixes with poor mixing effect, respectively, without going throughPremixed Q-3 feed system and non-premixed Q-5 feed system. As can be seen from the data in Table 4, the indexes of the comparative examples are not as good as those of the invention, the fiber time is less than or equal to 70s, the rapid filling can be realized, the curing time is less than or equal to 100s, the rapid demoulding can be realized, the completely filling effect is realized, the production efficiency is improved, and the cost is saved. Meanwhile, the polyurethane foam obtained by the scheme of the invention has low density and core density less than or equal to 27kg/cm 3 The heat insulation performance is good, the heat conductivity coefficient is less than or equal to 19 mW/(m.K), the foam cost is low, and the comprehensive performance is good.
Claims (9)
1. A method for premixing isocyanate, comprising the steps of:
(1) Raw material preparation:
isocyanate, the content of insoluble matters in the isocyanate is less than or equal to 0.02wt%;
an inert compound A, the moisture of the inert compound A being < 0.005wt%;
the inert compound A is an inert liquid foaming agent and/or an inert gaseous foaming agent;
(2) Mixing: introducing isocyanate and an inert compound A into a static mixer, and mixing to obtain a premix B; the weight ratio of the inert compound A to the isocyanate is 1: 8-20, wherein the temperature of the raw materials in the static mixer is controlled to be 5-22 ℃, and the viscosity of the premix B at 5 ℃ is less than 800 mPas.
2. A premixing method as claimed in claim 1, characterized in that the relative humidity in the chamber of the static mixer is less than or equal to 10% before the raw materials enter.
3. The premixing method according to any one of claims 1 to 2, wherein the isocyanate is at least one of polymethylene polyphenyl isocyanate, toluene diisocyanate or modified isocyanate.
4. A premixing process according to claim 3, characterized in that the modified isocyanate is polymethylene polyphenyl isocyanate or toluene diisocyanate modified with polyether polyols, bio-based polyols, carbon dioxide based polyols or polyester polyols.
5. The method according to any one of claim 1 to 2, wherein the inert liquid foaming agent is n-pentane, isopentane, cyclopentane, 1,3, at least one of pentafluorobutane, cis-1, 4-hexafluoro-2-butene, 1-chloro-3, 3-trifluoropropene.
6. A premixing method according to any one of claim 1 to 2, characterized in that, the inert gaseous foaming agent is n-butane, isobutane, 1, 3-tetrafluoropropene 2, 3-tetrafluoropropene, 1, 2-tetrafluoroethane, 1-difluoroethane, 1,3, one or more of pentafluoropropane and hexafluoropropylene.
7. A method for rapidly filling a mold cavity with foaming stock solution, which is characterized by comprising the following steps:
(1) Premixing liquid isocyanate and an inert compound A by using the premixing method of any one of the isocyanates in claims 1-6 to obtain a premix B, wherein the viscosity of the premix B at 5 ℃ is less than 800 mPas;
(2) Regulating the temperature of the premix B to 5-22 ℃ and regulating the temperature of the combined polyether to 12-32 ℃;
(3) Premix B is mixed with the combined polyether to form a foaming stock solution, the foaming stock solution is injected into the mold cavity at a set pressure, and the set pressure is maintained up to the solidification of the foam.
8. The method of claim 7, wherein the foaming stock solution consists of the following components in parts by weight:
81-139 parts of combined polyether;
133-198 parts of premix B;
wherein the combination polyether comprises:
50-97 parts of polyether polyol;
0-20 parts of bio-based polyol;
0-20 parts of carbon dioxide-based polyol;
0-20 parts of polyester polyol;
2-5 parts of an amine catalyst;
1-4 parts of a surfactant;
0-15 parts of a foaming agent;
1.3-2.1 parts of water.
9. The method of claim 7 or 8, wherein the cure time is less than 100 seconds.
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| JP2007051172A (en) * | 2005-08-12 | 2007-03-01 | Central Glass Co Ltd | Premix for rigid polyurethane foam or polyisocyanurate foam, foam and method for producing the same |
| CN110105520A (en) * | 2019-05-05 | 2019-08-09 | 深圳市盈石科技有限公司 | A kind of heat preservation hard polyurethane foams and preparation method thereof |
| CN111320737A (en) * | 2020-04-13 | 2020-06-23 | 南京红宝丽聚氨酯有限公司 | Polyurethane raw material composition, preparation method and application of polyurethane rigid foam |
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| EP3470446A1 (en) * | 2017-10-16 | 2019-04-17 | Covestro Deutschland AG | Rigid polyurethane foam system and application thereof |
| CN110343227A (en) * | 2019-08-09 | 2019-10-18 | 南京红宝丽聚氨酯有限公司 | A kind of hard polyurethane foams of extremely-low density and preparation method thereof |
| CN112724448B (en) * | 2020-12-30 | 2021-12-24 | 南京红宝丽聚氨酯有限公司 | Low-density and low-temperature-resistant polyurethane foam and preparation method thereof |
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| JP2007051172A (en) * | 2005-08-12 | 2007-03-01 | Central Glass Co Ltd | Premix for rigid polyurethane foam or polyisocyanurate foam, foam and method for producing the same |
| CN110105520A (en) * | 2019-05-05 | 2019-08-09 | 深圳市盈石科技有限公司 | A kind of heat preservation hard polyurethane foams and preparation method thereof |
| CN111320737A (en) * | 2020-04-13 | 2020-06-23 | 南京红宝丽聚氨酯有限公司 | Polyurethane raw material composition, preparation method and application of polyurethane rigid foam |
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