CN111454419B

CN111454419B - Full-water-blown semi-rigid PU foam

Info

Publication number: CN111454419B
Application number: CN202010246140.2A
Authority: CN
Inventors: 曹德忠
Original assignee: New Ziyuan Shanghai technology Development Co ltd
Current assignee: New Ziyuan Shanghai technology Development Co ltd
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2022-05-20
Anticipated expiration: 2040-03-31
Also published as: CN111454419A

Abstract

The invention relates to full-water-blown semi-rigid PU foam which comprises the following raw material components in parts by weight: 100 parts of polyether polyol; 100 portions of isocyanate and 135 portions; 10-12 parts of water; 1.6-2.0 parts of a crosslinking assistant; 1.0-1.2 parts of antioxidant; 1.2-2.3 parts of foam stabilizer; 0.6-0.8 part of catalyst; 10-15 parts of a flame retardant; 1.0-1.2 parts of pore forming agent. Compared with the prior art, the invention abandons the environmentally-friendly foaming agent HCFC-141B which is used for destroying the ozone layer since the nineties of the last century, and realizes the preparation of the full-water foaming semi-rigid PU foam.

Description

Full-water-blown semi-rigid PU foam

Technical Field

The invention belongs to the technical field of semi-rigid PU foam, and relates to full-water-blown semi-rigid PU foam.

Background

The semi-rigid Polyurethane (PU) foam is a foam between a soft foam and a rigid foam, the original foaming process of the semi-rigid PU foam is not environment-friendly, and some raw materials in a specific formula are forbidden, and some raw materials are forbidden.

Firstly, the use of CFC-11 in the production of PU rigid or semi-rigid foams is described.

Chlorofluorocarbon (CFC) compounds, developed in the united states in the 30 th 20 th century, began to be used in hard and semi-hard foams.

In the production process of Polyurethane (PU) rigid foam and semi-rigid foam, except for using chemical foaming agent water to react with polyisocyanate to generate CO₂For foaming, a physical blowing agent CFC-11 is generally used to achieve the requirement of reducing the density. Originally, CFC-11 had the advantages of non-flammability, boiling point suitable for foaming, low gas phase thermal conductivity, low toxicity, non-corrosiveness, low price, and simple foaming process, so that CFC-11 was used as a foaming agent for hard and semi-hard foams in polyurethane foams in the 60's of the 20 th century. The hard foam is widely applied to heat insulation materials of refrigerators, freezers and ice stores, heat insulation materials of buildings, storage tanks and pipelines, and the like. The PU semi-rigid foam is generally foamed into block foam, then cut into sheets with proper thickness, then compounded with the fabric, and then pressed and formed, and then the heat insulation and sound insulation of interior parts such as automobile roofs and the like are appliedEtc., which is lightweight, resistant to chemicals, resistant to bending, and not prone to fracture.

The amounts of CFC-11 in the PU rigid and semirigid foams are generally up to 5 to 25% of the total amount in the formulation, which should be considerable in the formulation.

In the 80 s of the 20 th century, the damage effect of CFC compounds on the earth environment is discovered, CFC-11 foaming agents are listed as chemical substances forbidden for a limited period, so that in the application field of different products of PU hard foam and semi-hard foam, different CFC substitute products are researched and developed by countries.

The methods and routes for substituting CFC-11 are not completely the same in all countries, and HCFC-141B (1, 1-dichloro-1-fluoroethane) is generally adopted as a substitute for CFC-11 in most countries and regions such as Europe, North America, Japan, etc.

HCFC-141B is used as a foaming agent for hard foam and semi-hard foam, and the influence on the foam performance needs to be considered besides manufacturability and cost.

Because the HCFC-141B has much lower chemical stability than CFC-11 (the life of HCFC-141B in the atmosphere is only about 8 years, and the life of CFC-11 is 60 years), the HCFC-141B has less influence on the environment than CFC-11, and the ODP value and GWP of HCFC compound are much lower than that of CFC, so that from the beginning of the last 90 th century, China gradually replaces CFC-11 with HCFC-141B as a valuable transitional substitute in the replacement process.

However, HCFC-141B is only a transitional substitute for CFC-11, it still has a damaging effect on the ozone layer, and HCFC-141B is forbidden in our country, so that the development of an environmentally friendly hard-bubble and semi-hard-bubble formulation is urgently needed.

The present invention has been developed to solve the above problems.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a full water foaming semi-rigid PU foam, which realizes the preparation of polyurethane semi-rigid foam between soft foam and rigid foam by only using water as a foaming agent.

The purpose of the invention can be realized by the following technical scheme:

the full-water foaming semi-rigid PU foam comprises the following raw material components in parts by weight:

preferably, the polyether polyol is high-activity polyether, polymer polyether and hard foam polyether, wherein the content of the high-activity polyether is 20-30 parts, the content of the polymer polyether is 25-30 parts, and the content of the hard foam polyether is 45-50 parts.

More preferably, the high activity polyether can be purchased from Jiangsu Changhua polyurethane technology Co., Ltd, and the grade is preferably CHE-330N, the hydroxyl value is 33.5-36.5mg KOH/g, the water content is less than or equal to 0.05 wt%, the pH value is 5-7, and the viscosity is 750-.

More preferably, the polymer polyether can be purchased from Shandong Lanxindong Daihuai chemical industry, Inc., and is preferably available from Shandong Lanxingdong chemical industry, Inc., with the trade mark POP36/28, etc., the hydroxyl value is 25-29mg KOH/g, the water content is less than or equal to 0.05 wt%, the pH value is 6-9, and the viscosity is less than or equal to 3000mPa s/25 ℃.

More preferably, the hard foam polyether can be purchased from Tanking Ningwu New Material development Co., Ltd, and the preferred mark is NJ-4110, the hydroxyl value is 430-470 mg-KOH/g, the water content is less than or equal to 0.2 wt%, the pH value is 9-12, and the viscosity is less than or equal to 4000-6000 mPa-s/25 ℃; or the preferred mark is NJ-403, the hydroxyl value is 370-390mg KOH/g, the water content is less than or equal to 0.1wt percent, the pH value is 5-8, and the viscosity is less than or equal to 1400-2200mPa s/50 ℃.

Preferably, the isocyanate is a compound of Toluene Diisocyanate (TDI), diphenylmethane diisocyanate (MDI) and/or liquefied MDI, two or three of the isocyanate, the diisocyanate, the diphenylmethane diisocyanate (MDI) and/or the liquefied MDI can be selected selectively, and the mass ratio can be determined according to the requirements of the product, such as TDI: MDI: liquefied MDI ═ 1:1:8, TDI: liquefied MDI 2:8, TDI: liquefied MDI is 3: 7. More preferably, the isocyanate is available from Corswertia or Hensman company, and the specific brand can be any one or more selected from the following:

TDI-80, NCO mass fraction 48.2%, relative density (20 deg.C) 1.22, freezing point 11.5-14 deg.C, viscosity (20 deg.C) 3.2 mPa.s;

the trade name of 44V20, NCO mass fraction of 30.5% -32.5%, relative density (20 ℃) of 1.22, viscosity (25 ℃) of 160-240 mPas and functionality of 2.7;

5005, NCO mass fraction 30.0% -31.5%, relative density (25 ℃)1.23, viscosity (25 ℃)170-270 mPas and functionality 2.7;

the trade name is 2050, the NCO mass fraction is 30.6-31.5%, the relative density (25 ℃) is 1.23, and the viscosity (25 ℃ CPS) is 130.

Preferably, the crosslinking assistant is a crosslinking agent and/or a chain extender, and the crosslinking assistant mainly has the function of improving the mechanical property of the foam, wherein the chain extender is a compound containing two functionalities, and the crosslinking agent is a compound containing three or four functionalities. More preferably, the chain extender is one or more of ethylene glycol, 1, 4-butanediol or diethylene glycol. More preferably, the crosslinking agent is one or more of diethanolamine, triethanolamine or ethanolamine.

The semi-rigid PU foam can generate a large amount of heat in the foaming process, the heat is dissipated by means of a physical foaming agent HCFC-141B in the original foaming formula, and the burning core in the middle of the foam is avoided, and the HCFC-141B is not environment-friendly, so that the invention ensures that the burning core in the middle of the foam is avoided by adopting a proper amount of antioxidant, preferably, the antioxidant is antioxidant 264(2, 6-di-tert-butyl-p-cresol), antioxidant 1010 (pentaerythritol ester), butyl or octylated diphenylamine (Irganox5057 and Naugard PS 30), or hindered phenol antioxidant (such as antioxidant 1135 and the like) or antioxidant CS-17.

Preferably, the foam stabilizer is a silicone compound, especially a polydimethylsiloxane copolymer or a polyoxyalkylene copolymer such as silicone oil. Taking silicone oil as an example, because the raw materials of the semi-rigid PU foam comprise both soft foam polyether and hard foam polyether, the foam stabilizer also needs to use both soft foam silicone oil and hard foam silicone oil, and meanwhile, the soft foam silicone oil and the hard foam silicone oil need to be well matched, so that the effects of stabilizing the foam and controlling foam holes can be achieved. Furthermore, since the rigid foam PU is closed-cell, the high resilience foam needs to be open-cell, and the cells are broken by extrusion in the conventional manner. The semi-hard PU foam of the invention also needs open-cell foam, but the production process can not depend on extrusion to break the cells, the foam needs to be opened during foaming, which needs to select proper types and proportion of silicone oil, preferably adopts the composition of hard foam silicone oil and soft foam silicone oil, and the mass fraction of the hard foam silicone oil is 0.6-1.1 parts, and the mass fraction of the soft foam silicone oil is 0.6-1.2 parts. Preferably, the silicone oil may be designated by Lb27, DC2525, L3415, Lb900, HP8911, DC2585, HP8920, and the like.

In the semi-rigid PU foams of the present invention, two or more catalysts are used to adjust the balance of the rate of chain growth and the rate of crosslinking. Preferably, the catalyst is a tertiary amine catalyst, and is preferably a compound of two or more of N, N' -dimethyl piperazine, N-dimethyl cyclohexylamine, tetramethyl butanediamine, N-ethyl morpholine, triethylene diamine, dimethyl ethanolamine or triethylamine.

In addition, the foaming reaction and the gelling reaction are balanced so that the semi-rigid foam is neither closed cell nor open celled. First, to balance the foaming reaction with the gelling reaction, very fine adjustments are made. As the block foam cannot be broken by rolling as the molded high resilience foam is, the proportion of the composite catalyst and the silicone oil is important, and a proper amount of the pore-forming agent is added. In order to avoid burning cores or burning holes in the middle of the block bubble, an antioxidant must be added. Further, if necessary, 1.0 to 1.2 parts of a cell opener may be added, and the foam is likely to shrink. The requirement on the opening time of the opening agent is strict, the addition amount of the opening agent is too much, the cells can be spliced, the cell structure is too rough, and if the addition amount of the opening agent is too little, a chemical reaction forms a cell film with higher strength, so that the effective opening effect cannot be achieved. The opening time is generally controlled to be about 8-15s, namely the time for the foam to rise to the top of the mold. Preferred pore formers are 1900G, HP292, SK1900, KF501, and the like.

The conventional semi-rigid PU foam is not flame-retardant, and the flame retardant is a common method when the conventional semi-rigid PU foam achieves the flame-retardant effect, and a certain flame-retardant effect can be achieved only when the conventional semi-rigid PU foam achieves a certain amount. Flame retardants are of two types, one additive and one reactive. The additive flame retardant can be selected from halogenated phosphate flame retardants which have good intermiscibility with polyether polyol and obvious flame retardant effect, and the available halogenated phosphate flame retardants have the following varieties: tris (2-chloropropyl) phosphate (TCPP), tris (2-chloroethyl) phosphate (TCEP), bishydroxyethylene glycol phosphate, and the like. The reactive flame retardant, such as dimethyl methyl phosphate (DMMP), has high phosphorus content, excellent flame retardant performance, no halogen, less addition and convenient use, and has the double functions of reducing viscosity and retarding flame. The reactive flame retardant may be triethyl phosphate, ethyl diethyl phosphate, or the like. In addition, it should be noted that the additive flame retardant will migrate and slowly volatilize during the use of the material, while the reactive flame retardant is chemically bonded to the polyurethane material, so as to overcome the disadvantages of the additive flame retardant. In addition to the above two flame retardants, there are also inorganic solid additive type flame retardants, which may be selected from expanded graphite powder, aluminum hydroxide powder, and the like. Preferably, the flame retardant is selected from one or more of halogenated phosphate flame retardant, reactive flame retardant, expanded graphite or aluminum hydroxide.

Preferably, pigment is also added into the semi-rigid PU foam, the function of the pigment is mainly to provide color and luster, and the specific addition amount can be as required, such as 0.5 weight part.

Detailed Description

The present invention will be described in detail with reference to specific examples. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

The test standards and instrumentation for each property of the present invention are shown in table 1 below.

TABLE 1

In the following examples, the highly reactive polyether is obtained from Jiangsu Changhua polyurethane science and technology Co., Ltd, and its trade name is preferably CHE-330N, hydroxyl value is 33.5-36.5mg KOH/g, water content is less than or equal to 0.05 wt%, pH value is 5-7, viscosity is 750-950mPa s/25 ℃. The polymer polyether is purchased from Shandong Lanxindong Daihuai chemical industry, Limited company, and preferably has the trade mark POP36/28, the hydroxyl value of 25-29mg KOH/g, the water content of less than or equal to 0.05 wt%, the pH value of 6-9 and the viscosity of less than or equal to 3000mPa s/25 ℃. The hard foam polyether can be purchased from Tanking Ningwu New Material development Co., Ltd, and the preferred trade name is NJ-4110, the hydroxyl value is 430-470 mg-KOH/g, the water content is less than or equal to 0.2 wt%, the pH value is 9-12, and the viscosity is less than or equal to 4000-6000 mPa-s/25 ℃; or NJ-403, a hydroxyl value of 370-390mg KOH/g, a water content of less than or equal to 0.1 wt%, a pH value of 5-8, and a viscosity of less than or equal to 1400-2200mPa s/50 ℃. The isocyanate is compounded by the following four components in a mass ratio of 1:1: TDI-80, NCO mass fraction 48.2%, relative density (20 deg.C) 1.22, freezing point 11.5-14 deg.C, viscosity (20 deg.C) 3.2 mPa.s; the trade name of 44V20, NCO mass fraction of 30.5% -32.5%, relative density (20 ℃) of 1.22, viscosity (25 ℃) of 160-240 mPas and functionality of 2.7; 5005, NCO mass fraction 30.0% -31.5%, relative density (25 ℃)1.23, viscosity (25 ℃)170-270 mPas and functionality 2.7; the trade name is 2050, the NCO mass fraction is 30.6-31.5%, the relative density (25 ℃) is 1.23, and the viscosity (25 ℃ CPS) is 130.

The remainder, unless otherwise indicated, are all conventional commercial materials or conventional processing techniques in the art.

In the preparation process of the following embodiments, firstly, isocyanate is independently used as a material B at the material temperature of 20-28 ℃, the other components are mixed to prepare a material A, then the material A and the material B are mixed, fully stirred for 6-8s by a mechanical stirrer, poured into a mold (at normal temperature), kept for 3-5min, demoulded, and placed for 24h to test.

The mould used in the above embodiment is a box without a cover, when the mixed raw materials are poured into the mould, the raw materials can be freely foamed (i.e. foamed at normal temperature and normal pressure), after the raw materials are foamed to the top, the semi-hard PU foam can be taken out after 3-5min, then the semi-hard PU foam is cut into pieces according to the required thickness of the product, and the next procedure is to compound non-woven fabrics on two sides of the semi-hard PU foam into pieces, and then the non-woven fabrics are subjected to hot press molding to obtain various products.

The weight ratios of the components of each example are shown in table 2 below.

TABLE 2

In the above examples, the composite catalyst is prepared by compounding catalyst a and catalyst B according to a mass ratio of 1:0.5-0.7, wherein catalyst a is N, N-dimethylcyclohexylamine, and catalyst B is triethylenediamine.

The products obtained in the above examples and comparative examples were tested for density, dimensional stability, high temperature resistance, flame retardancy, mildew resistance and compression set, and the specific performance structures are shown in Table 3 below.

TABLE 3

Note: "-" indicates shrinkage.

As can be seen from the above Table 3, the foam products supported by the process of the present invention have good dimensional stability, flame retardancy, high temperature resistance, etc., and the whole foam product has more open-cell distribution and good touch resilience, and is a semi-rigid PU foam product meeting the requirements. While the properties of the foamed article obtained in comparative example 1 were observed, which used only a hard foam silicone oil as a foam stabilizer, although the foamed article obtained was also excellent in dimensional stability, high temperature resistance and flame retardancy, the foamed article obtained had a small number of open cells, a hard foam touch and poor resilience, and was a relatively hard foamed article.

The following table 4 shows the formula ratios of comparative examples 2 to 4.

TABLE 4

The results of the performance tests of comparative examples 2 to 4 above are shown in table 5 below.

TABLE 5

From the test results in table 5 above, it can be seen that if no antioxidant is used, there is a significant problem of core burning in the middle of the final foamed product, making it difficult to form the product normally. Further, comparing comparative example 3 with example 1, it is known that when the cell opening agent is added excessively, a significant splicing phenomenon occurs between cells, so that the cell opening diameter is excessively large, the cell structure is excessively coarse, and the strength is insufficient. In contrast, when the amount of the cell opener added is smaller in comparative example 4 compared with example 1, the number of open cells is correspondingly reduced, which is analyzed to be that the cell membrane formed by the reaction is broken and opened due to the insufficient amount of the cell opener during the foaming process. When the amount of the soft foam silicone oil added is too large, incomplete opening also occurs in comparison with the comparative example 5 and the examples.

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.

Claims

1. The full-water-blown semi-rigid PU foam is characterized by comprising the following raw material components in parts by weight:

100 parts of polyether polyol;

100 portions of isocyanate and 135 portions;

10-12 parts of water;

1.6-2.0 parts of a crosslinking assistant;

1.0-1.2 parts of antioxidant;

0.6-0.8 part of catalyst;

10-15 parts of a flame retardant;

1.0-1.2 parts of a pore-forming agent;

and a foam stabilizer;

the polyether polyol is high-activity polyether, polymer polyether and hard foam polyether, wherein the content of the high-activity polyether is 20-30 parts, the content of the polymer polyether is 25-30 parts, and the content of the hard foam polyether is 45-50 parts;

the crosslinking assistant is a crosslinking agent and/or a chain extender, wherein the chain extender is a compound containing two functionalities, and the crosslinking agent is a compound containing three or four functionalities;

the foam stabilizer is an organic silicon compound and is formed by mixing soft foam silicone oil and hard foam silicone oil, wherein the weight parts of the soft foam silicone oil are 0.5 part, 0.6 part or 0.8 part, and the weight parts of the hard foam silicone oil are 1 part.

2. The all-water blown semi-rigid PU foam according to claim 1, wherein the isocyanate is a combination of toluene diisocyanate, diphenylmethane diisocyanate and liquefied MDI.

3. The all-water blown semi-rigid PU foam according to claim 1, wherein the chain extender is one or more of ethylene glycol, 1, 4-butanediol or diethylene glycol;

the cross-linking agent is one or the combination of two of diethanolamine and triethanolamine.

4. The all-water blown semi-rigid PU foam according to claim 1, wherein the antioxidant is antioxidant 264, antioxidant 1010, hindered phenol antioxidant, butyl or octylated diphenylamine.

5. The all-water blown semi-rigid PU foam according to claim 1, wherein said catalyst is a tertiary amine catalyst selected from the group consisting of N, N' -dimethylpiperazine, N-dimethylcyclohexylamine, tetramethylbutanediamine, N-ethylmorpholine, triethylenediamine, dimethylethanolamine or triethylamine in combination of two or more thereof.

6. The fully water blown semi-rigid PU foam according to claim 1, wherein the flame retardant is one or more selected from the group consisting of halogenated phosphate flame retardants, reactive flame retardants, expanded graphite, and aluminum hydroxide.

7. An all-water blown semi-rigid PU foam according to claim 1, wherein a pigment is further added to the semi-rigid PU foam.