WO2006089471A1 - One-component polyurethane foam having low shrinkage, and its preparation - Google Patents

Abstract

An one-component polyurethane foam having low shrinkage and its preparation are disclosed herein. The inventive polyurethane foam is prepared by reacting polyester polyol or polyether polyol, amine catalyst, oxazolidines compound, plasticizer and/or flame retardant, solubilizer, foam stabiliser, polyisocyanate, propellant and/or foaming agent, and the like. The polyurethane foam of the present invention has low shrinkage of about 5.4%, measured according to Standard GB 8811, so as to fulfill the requirements to one-component polyurethane foam by the construction industry, and also resolve problems such as detachment between the foam and wall body, the formation of a cold bridge of wall body, water leakage and the like.

Description

 Low shrinkage rate single component polyurethane foam and preparation method thereof

 The present invention relates to a polyurethane foam and a preparation method thereof, and more particularly to a one-component polyurethane foam and a preparation method thereof. Background technique

 One-component polyurethane foam (OCF for short) is the product of the cross-combination of aerosol technology and polyurethane foam technology. It is a special polyurethane product that packs polyurethane prepolymer, foaming agent, catalyst and other components into a pressure-resistant aerosol can. When the material is ejected from the aerosol can, the enamel-like polyurethane material rapidly expands and solidifies to react with the air or the moisture in the contacted substrate to form a bubble. The cured OCF foam has many effects such as caulking, bonding, sealing, heat insulation and sound absorption. It is an environmentally-friendly, energy-saving and easy-to-use building material, which can be used for sealing and sealing, filling and filling, and fixing. , thermal insulation, especially suitable for sealing and waterproofing between plastic steel or aluminum alloy doors and windows and walls.

 At present, almost all production of OCF adopts the "in-can polymerization" production process, that is, first, the polyol, the catalyst, the auxiliary agent and the isocyanate are poured into the aerosol can, and after sealing the valve, the foaming agent (propellant) is charged. Then, the shaker is shaken sufficiently to uniformly mix and react the materials in the tank to form a mixture of polyurethane prepolymer, auxiliary agent and propellant, thereby obtaining a canned OCF product.

Since the one-component polyurethane foam has been foamed twice, the polyurethane prepolymer is first blown into a foam by a propellant, and then the scorpion continues to react with moisture in the air to form co ₂ , further causing the scorpion Expansion, therefore, finally forming a solidified foam with a lower density and a certain closed cell ratio (15-30 kg/m ³ ) o With the escape of gas in the foam, such a low density polyurethane foam has a large shrinkage tendency. The size of the shrinkage has a large effect on its filling and sealing effect. For example, when OCF is used for sealing between plastic steel doors and windows and cement walls, if the shrinkage rate is too large, it will cause foaming. Detach from the wall to form a gap, causing a cold bridge or water leakage.

 Generally, for low-density polyurethane foams with a certain closed cell ratio, dimensional stability can be improved by appropriately increasing the degree of crosslinking of the system and increasing the strength of the microporous membrane walls, which has been proven in two-component foams. It works well. However, for OCF, the greater the cross-linking degree of the system, the higher the viscosity of the polyurethane prepolymer, and the worse the storage stability of the OCF tank. In severe cases, the gel appears in the tank and cannot be shaken, resulting in product scrapping. . Therefore, the improvement of the functionality of the OCF system is limited, so that the dimensional stability problem cannot be solved well.

The method for reducing the shrinkage of OCF disclosed in British Patent GB1086609, GB1175717 is: using an aerosol can having two lumens, the polyol and part of the propellant component and the isocyanate and part of the propellant component are respectively loaded into two In the chamber, the valve is opened when in use, and the two streams are passed through a suitable mixture (such as a static mixer) to form a bubble. This idea draws on the two-component high-functionality polyurethane foam system. The main disadvantage is the use of double-cavity aerosol cans and static mixers. The packaging cost is high. Once the valve is opened, it must be used up, otherwise it will be mixed. The material behind will block the mixer. U.S. Patent No. 4,263,412 uses the method of: using an aerosol canister with a built-in plastic pouch, loading the polyurethane prepolymer and part of the propellant into the inner bag, and charging the remaining propellant into the aerosol canister, due to the propellant The dual function of the driving material and the foaming agent, the separate loading of the propellant, is equivalent to reducing the foaming agent, increasing the density of the foam, thereby improving the dimensional stability of the foam. U.S. Patent 4,258,140 uses a polyol containing N to prepare a polyurethane prepolymer which reacts rapidly with moisture in the air to provide dimensionally stable foam. The method disclosed in German Patent No. DE4303887 is: adding a small amount of saturated aliphatic hydrocarbon having a viscosity of 110-230 mPa.s@25 °C to the material system, increasing the opening ratio of the foam and improving the dimensional stability of the foam. The method of the world patent WO02090410 is: adding a monofunctional small molecule alcohol in the preparation of the prepolymer, and by reducing the functionality of the prepolymer, a bubble having a high open porosity is obtained, and the shrinkage rate is reduced. Obviously, by improving the opening ratio, the dimensional stability of the foam is improved, and the sealing, heat insulating and waterproofing effects are not obtained. Although the above patents are mentioned How to reduce the shrinkage of OCF foam, but did not give specific data. The results of the National Polyurethane Foam Filler Standard Preparation Group on the dimensional stability of commercially available imported OCF have shown that most imported OCF products have a shrinkage of 7-12% (gun type), such as the shrinkage of US FOMO products. The rate is 8.5%, the shrinkage of the German Hago product is 8%, and the WELLGO OCF is 7.4%. Summary of the invention

 The technical problem to be solved by the present invention is to disclose a low-shrinkage single-component polyurethane foam and a preparation method thereof to overcome the above-mentioned drawbacks existing in the prior art.

 The low shrinkage single component polyurethane foam of the present invention is prepared by using the following raw materials - (a) polyester polyol or polyether polyol;

 Said polyester polyol or polyether polyol has a functionality of 2-4, a molecular weight of 400-10000, a hydroxyl number of 100" 00 mg KOH / g, preferably 150-250 mg KOH / g;

 The polyether polyol is preferably a polyglycolide (PPO) type, the initiator of which is glycerin, ethylenediamine, diethylene glycol or a mixture thereof, for example, GQ210 produced by Shanghai Gaoqiao Petrochemical No. 3 Factory. Products of GE-310 or TMN500, and products of TMN1000 produced by Tianjin Petrochemical No.3. Polyether polyols may also contain flame retardant elements such as polyethers containing halogen, nitrogen or phosphorus, such as SOLVAY FLUOR AND DERIVATE GmbH. The company's products are PHT-4, AMGARD V82, IXOL M125;

The preferred polyester polyol is an aromatic ring-containing polyester having a functionality of 2 to 3, which is obtained by polycondensation of a polycarboxylic acid or an acid anhydride with a polyhydroxy compound, and the carboxylic acid used may be aliphatic and aromatic. a mixture of carboxylic acids, but at least one of which is an aromatic ring-containing carboxylic acid, which may be commercially available, such as those manufactured by STEPANOL COMPANY under the designations PS3152, PS-2412, PS-2352, and COIM COMPANY. The product number is ISOEXTER 360, 4537; (b) a catalyst in an amount of 1-3% by mass of the polyester polyol or the polyether polyol; the catalyst is an amine compound for the polyurethane reaction, preferably pentamethyldiethyltriamine (Polycat 5), dimethyl One of cyclohexylamine (DMCHA), N-methylmorpholine, dimethylethanolamine (DMEA) or dimorpholine diethyl ether (DMDEE);

 (c) The oxazolidine compound is used in an amount of from 1 to 5% by mass based on the mass of the polyester polyol or the polyether polyol; the oxazolidine compound is a reactive latent curing agent, particularly hydroxyoxazolidine. The reaction of oxazolidine with a portion of the isocyanate group (-NCO) reduces the functionality of the system and reduces the viscosity of the material in the tank, ensuring storage stability of the contents of the tank. However, when OCF is used, the ejected material is in contact with air, and the oxazolidine structure immediately reacts with water in the air to form amino groups and primary hydroxyl groups (the reaction rate is much faster than the reaction rate of -NCO and water), newly formed The amino group and the primary hydroxyl group react rapidly with -NCO to crosslink the PU foam, thereby reducing the shrinkage of the foam and improving the dimensional stability of the OCF. The oxazolidine compound can be commercially available, such as TECO. The product of ODW-201 produced by Chemical Co., Ltd. has the following structural formula:

其中 Rf- CH ^, n=l-3, R₂可以是 CH₃,或 -C₂H₅；

Wherein Rf-CH^, n=l-3, R ₂ may be CH ₃ or -C ₂ H ₅ ;

 (d) A plasticizer/flame retardant in an amount of 70-120% by mass of the polyester polyol or polyether polyol, preferably 80-100 °/. The preferred plasticizing/flame retardant is trichloroisopropyl phosphate (TCPP) or chlorinated paraffin;

(e) a solubilizing agent in an amount of from 3-15% by mass of the polyester polyol or polyether polyol, preferably from 4 to 8%; The solubilizing agent is used to increase the compatibility of the non-polar propellant with the polyurethane. The preferred solubilizing agent is N-methylpyrrolidone (NMP), dichloromethane (MC) or diethyl succinate (DBE);

 (f) a foam stabilizer, in an amount of 2-3% by mass of the polyester polyol or polyether polyol;

 The foam stabilizer is selected from the group consisting of surfactants for polyurethane rigid foam or polyisocyanate foam, and the foam stabilizer is polyethylene oxide and epoxidized graft modified silane, and commercially available products such as German Gauss can be used. Mitt's products are graded B8404, B8460 or B8462, such as those manufactured by Compton, Inc. under the designations L-6900, L-5440, L-5420, L-5421, such as those produced by American Gas Products. Products with the grades DC5604, DC193, DC5589, DC5103;

(g) isocyanate, in an amount of from 1.5 to 4 times, preferably from 1.8 to 2.5 times, the mass of the polyester polyol or the polyether polyol;

 The isocyanate is preferably a polyphenylmethane polyisocyanate (p-MDI) having a functionality of 2.2 to 2.9, toluene diisocyanate (TDI) or a modified form thereof, and a commercially available product such as the product SUP5005 manufactured by HUNTSMAN CORP. The product of SUP2085, the product of MSFS produced by BASF CORP., the product of 44W20L produced by BAYER CORP., the product of PM-200 by Yantai Wanhua Polyurethane Co., Ltd.;

 () propellant/foaming agent, in an amount of 80 to 110% by mass of the polyester polyol or polyether polyol; the propellant/foaming agent is selected from compounds having an ozone depletion potential (ODP) of zero or a low ODP value, Preferred are ether compounds, hydrochlorofluorocarbons, hydrofluorocarbons or low molecular alkanes, and suitable propellant/foaming agents are selected from the group consisting of dimethyl ether, propane, 1,1,1,2-tetrafluoroethane (HFC). -134a) or dichlorodifluoromethane (F12) and the like.

According to a preferred embodiment of the present invention, a color paste such as a yellow pigment, a green pigment or the like may be added as needed to increase the color of the foam, and an antioxidant such as 2,6-di-tert-butyl-p-methylphenol, hydrazine, hydrazine. Additives such as '-diphenyl-p-phenylenediamine, the amount of which is 0.3-3% by mass of the polyester polyol or polyether polyol; The preparation method of the low shrinkage single-component polyurethane foam of the invention comprises the following steps: polyol polyether or polyester polyol, catalyst, oxazolidine compound, plasticizer/flame retardant, solubilizer, foam The stabilizer and the equal components are uniformly mixed to obtain a polyurethane composition (I);

 The isocyanate and polyurethane composition (I) are sequentially poured into the aerosol can;

 The propellant/foaming agent is filled into the aerosol can to obtain the product, which can be used after being placed upright for 24 hours.

 Add color paste and anti-aging agent as needed;

The low-shrinkage single-component polyurethane foam of the present invention is used in the same manner as the conventional method, but has a low shrinkage rate and is tested by the GB8811 standard, and the shrinkage rate is only 5.4%, which can satisfy the construction industry for a single group. The requirement of sub-bubble; solves the problem of peeling between the foam and the wall encountered in the current construction site construction, causing cold bridge or water leakage in the wall. The invention adopts the reaction of oxazolidine with a part of isocyanate group (-NCO), which reduces the functionality of the system, reduces the viscosity of the material in the tank, and ensures the storage stability of the material in the tank. However, when OCF is used, the ejected material is in contact with air, and the oxazolidine structure immediately reacts with water in the air to form amino groups and primary hydroxyl groups (the reaction rate is much faster than the reaction rate of -NCO and water), newly formed The amino group and the primary hydroxyl group react rapidly with -NCO to act as a cross-linking PU foam, thereby reducing the shrinkage of the foam and improving the dimensional stability of the OCF.

 The raw materials used in the examples are as follows:

 GE310, polyether polyol, with a functionality of 3, a molecular weight of 1000, a hydroxyl number -.

165mgKOH/g, produced by Shanghai Gaoqiao Petrochemical Plant No.3

 GE210, polyether polyol, hydroxyl value: llOmgKOH / g, Shanghai Gaoqiao Petrochemical Third Factory

 HD 204 polyester polyol with aromatic ring, with a functionality of 2.1 and a molecular weight of 580 hydroxyl:

205mgKOH/g, Shanghai Dongyuan Fine Chemical Company. B-8870, silane foam stabilizer, Germany Gossmit.

 L-5340, polyethylene oxide modified silane foam stabilizer, Compton, USA

 DMDEE dimorpholine diethyl ether, catalyst, US Gas Products.

 TCPP Trichloroethyl isopropanol phosphate, flame retardant, Zhejiang Tiancheng Chemical Co., Ltd. S-42, chlorinated paraffin, Shanghai chlor-alkali company

 DESMODUR 44V20L, polymethylene polyisocyanate., Germany Bayer

 PM-200 polymethylene polyisocyanate. Yantai Wanhua Polyurethane Company.

 SUPRASEC 5025, Polymethylene Polyisocyanate., USA HUNTSMAN HTM5007 Modified Toluene Diisocyanate, Shanghai Bohai Chemical Co., Ltd.

 ODW-201, Hydroxyoxazole, Shanghai Bohai Chemical Co., Ltd.

 DBE, diethyl succinate

 NMP, N-methylpyrrolidone

 The formulation in Table 1 is in parts by mass.

 Example 1

 According to the formulation listed in Table 1, the polyol polyether or polyester polyol, catalyst, oxazolidine compound, plasticizer/flame retardant, solubilizer, foam stabilizer and other components are uniformly mixed. Polyurethane compound (I), the polymethylene polyisocyanate and the compound (I) are sequentially poured into the aerosol tank according to the ratio, and then the valve is sealed, and then the propellant propane (LPG) and dimethyl ether are sequentially charged ( After DME), shake the aerosol canister fully for at least 1 minute. After being placed for 24 hours, the foam was sprayed out, and after solidification and characterization, physical and mechanical properties such as dimensional stability were measured, and the test was carried out by Q/IEFA 21-1999 standard, and the results are shown in Table 1.

 Example 2-5

According to the formulation listed in Table 1, the process is the same as in Example 1. Examples 2-5 are by changing the polyol, the foam stabilizer and the flame retardant/plasticizer and isocyanic acid in the formulation under the conditions of using oxazolidine. A one-component foam prepared from an ester. The test was carried out by the Q/IEFA 21-1999 standard, and the results are shown in Table 1.

 Example 6-8

 According to the formulation listed in Table 1, the process is the same as in Example 1. Examples 6-8 are comparative examples of oxazolidine-free formulations. These foams have poor dimensional stability and compression strength compared to foams formulated with oxazolidine.

 Table 1. Formulation and properties of one-component polyurethane foam

Example 1 2 3 4 5 6 7 8 Formulation

 GE310 100 80 70 100 100 80

 HD 204 100 30 100

GE210 20 20

 B8870 3 3 2.5 3 3

L-5034 3 2 3

 DMDEE 1 1.5 1.5 1.5 3 1.5 1.5 1.5

TCPP 54 54 30 54 54 54 54

S42 24 54

 ODW-201 2 1 2 3 5

 DBE 2 3 2 2 2 3

NMP 1 1

 DME 18 18 18 18 28 18 18 18

LPG 72 72 72 72 92 72 72 72

Desmodur44v20L 150 221 170 180 170 250

Suprasec5025 180

 HTM-5007 192

Performance. - Free bubble density,

Kg/m ³ 24 22 27 27 19 23 26 23 Compressive strength, KPa

48 56 46 52 42 41 40 46 Bond strength - Aluminum-aluminum 95 121 90 110 87 95 90 118

PVC-PVC 102 134 112 118 97 100 111 129 Dimensional change rate, % 7 5.4 8.5 7.7 5.8 11 14 10

 B3 B2 B3 B2 B3 B3 B3 B2 Flame retardant:

Claims

Rights request A low shrinkage one-component polyurethane foam which is prepared by using the following raw materials:  0) a polyester polyol or a polyether polyol;  (b) Amine compound catalyst in an amount of 1- or 1 part by mass of polyester polyol or polyether polyol 3%;  (c) The oxazolidine compound is used in an amount of 1-5% by mass of the polyester polyol or the polyether polyol; the structural formula of the oxazolidine compound is as follows:

Wherein Rf-CH-n, n=l-3, is CH ₃ , or -C ₂ H _5;  (d) a plasticizer/flame retardant in an amount of 70-120% by mass of the polyester polyol or polyether polyol, (e) a solubilizer in an amount of 3-15% by mass of the polyester polyol or polyether polyol;  (f) a foam stabilizer, in an amount of 2-3% by mass of the polyester polyol or polyether polyol;  The foam stabilizer is a polyethylene oxide and propylene oxide graft modified silicon germanium;  (g) isocyanate in an amount of from 1.5 to 2.5 times the mass of the polyester polyol or polyether polyol; (h) Advancing/foaming agent in an amount of 80 to 120% by mass of the polyester polyol or polyether polyol.  The low-shrinkage one-component polyurethane foam according to claim 1, wherein the polyester polyol or polyether polyol has a functionality of 2-4, a molecular weight of 400-10000, and a hydroxyl value. It is 100 ~ 400mg KOH / g. The low shrinkage one-component polyurethane foam according to claim 2, wherein the polyester polyol or the polyether polyol has a hydroxyl value of from 150 to 250 mg KOH/g. The low shrinkage single-component polyurethane foam according to claim 1, wherein the polyether polyol contains a flame retardant element.  The low-shrinkage one-component polyurethane foam according to claim 1, wherein the polyester polyol is an aromatic ring-containing polyester having a functionality of 2 to 3.  The low shrinkage single component polyurethane foam according to claim 1, wherein the catalyst is selected from the group consisting of pentamethyldiethyltriamine, dimethylcyclohexylamine, N-methylmorpholine, and One of methylethanolamine or dimorpholine diethyl ether.  7. The low shrinkage single component polyurethane foam according to claim 1, wherein the plasticizing/flame retardant is trichloroisopropyl phosphate or chlorinated paraffin.  The low-shrinkage one-component polyurethane foam according to claim 1, wherein the solubilizing agent is N-methylpyrrolidone, dichloromethane or diethyl succinate.  The low-shrinkage single-component polyurethane foam according to any one of claims 1 to 8, which further comprises a color paddle or/and an antioxidant, in an amount of polyester polyol or polyether polyol. 0.3~3% o  The method for preparing a low-shrinkage single-component polyurethane foam according to any one of claims 1 to 9, which comprises the following steps:  Polyol polyether or polyester polyol, catalyst, oxazolidine compound, plasticizer / flame retardant, solubilizer, foam stabilizer and the like are uniformly mixed to obtain a polyurethane composition (I);  The isocyanate and polyurethane composition (I) are sequentially poured into the aerosol can;  The propellant/foaming agent is filled into the aerosol can and mixed to obtain the product.