D E S C R I P T I O N

"NEW POLYOLS AND USES THEREOF"

Technical field of the invention

The present invention relates to a production process for non- alkoxylated Mannich base condensates (hereinafter Mannich Base); and to

Mannich bases with a high amine index that can be produced by this condensation process, and to the use of said products in the formulation of rigid polyurethane foams, particularly spray application foams.

Background of the invention

In recent years, the elimination of hydrochlorofluorocarbon (HCFC) compounds from formulations of polyurethane systems for environmental reasons has involved the adjustment thereof In the particular case of spray application polyurethane foams, which are in high demand in the construction sector where they are mainly used as thermal insulation, increasingly optimal formulas have been developed that are adapted to new generation foaming agents, hydrofluorocarbons (HFC). Polyurethane foam is produced by reacting a polyisocyanate compound with a polyol compound. A polyol is a compound that comprises several hydroxyl groups in its molecular structure and the most commonly used in formulations of polyurethane foams tend to be polyethers, polyesters or hydroxylated Mannich bases. The reaction medium for producing polyurethane will include flame retardants, catalysts of the polymerisation reaction of the polyisocyanate compound with the polyol compound (or gelling catalysts), catalysts of the reaction between the polyisocyanate compound and water (or foaming catalysts), silicone surfactants and physical foaming agents (e.g. HFC) and chemical foaming agents (water). All these elements that are present in the reaction medium tend to be mixed together with the polyol compound into what is known as the polyol component or formulated polyol.

Together, the polyisocyanate component plus the polyol component are known as a polyurethane system. Having made the necessary adjustments as a consequence of

eliminating HCFC, most companies in the sector are showing a great deal of interest in modifying the polyol component to improve its properties and those of the polyurethane foam produced by its reaction with a poiyisocyanate. it is of particular interest for polyurethane systems to retain their reactivity over time, which makes it possible, on the one hand, to increase their shelf life and, on the other, it can help to save catalysts. One factor that influences this is modifying the Mannich Base used in the formulation.

The production of alkoxylated Mannich bases (with propylene and/or ethylene oxide) has been disclosed in the polyurethane sector since 1964. Their production is extensively described in the bibliography, e.g. in GB1002272, US3297597, US4137265, US4525488, US4404121 , US4434277, EP405557, US4681965, US4883826, US 5120815 and ES 549703.

However, there are very few examples of Mannich bases that do not include ethylene oxide and/or propylene oxide, i.e. that are non-alkoxylated. The first of these dates back to 1966 and is disclosed in the patent GB 1139874 of 15 January 1969, assigned to Upjohn Co., a pioneer in producing alkoxylated Mannich bases. The patent discusses the possible use of a non-alkoxylated Mannich Base as a polyol and, despite admitting its lower stability, example number 3 (pages 10 and 11 ) shows the properties of the corresponding foams, which are fully accepted.

Several companies have subsequently marketed non-alkoxylated Mannich bases and this technology has gradually spread throughout the spray foam insulation sector. The instability of the non-alkoxylated polyol has been overcome by dilution with the other ingredients in the formulation, meaning that it is no longer an insuperable problem. Moreover, the lack of alkoxylation produces Mannich bases with a higher reactivity, better foam adherence and greater resistance to fire.

Other examples of the use of these Mannich bases as polyols are: M. lonescu et al, Chemical Bulletin of Polytechnic University of Timisoara, 2003, 46, 60, 1 ; T.H. Ferrigno, Rigid Plastic Foams, 2nd edition, Reinhold, New York (USA) 1967; M. lonescu et al, Cellular Polymers, 1994, 13, 1, 57; R. Brooks, Urethanes Technology, 1999, 16, 1, 34; J. M. Monsό et al "Spray system with improved fire resistance" (PU Expo 2001 ).

Another example of a formulation for flame-resistant rigid foams that include this type of non-alkoxylated compounds is that disclosed in patent

application US2003/0225174 A1 (Bayer Polymers LLC). This document discloses rigid polyurethane foams that can be produced by reacting a polyisocyanate component and a component containing a polyol compound corresponding to a non-alkoxylated Mannich base, which can be produced by reacting an aromatic compound (preferably a phenolic derivative), at least one aldehyde (preferably formaldehyde) and at least one alkanolamine (preferably diethanolamine).

All these documents disclose polyols that can be produced by condensation of phenol derivatives and aldehydes with alkanolamines following the Mannich reaction to produce non-alkoxylated compounds, i.e. compounds that are not subjected to reactions of, e.g. propoxylation of the hydroxyl groups of alkanolamine radicals.

One of the objectives of synthesising Mannich bases that can act as a polyol component in polyurethane foam formulations is to produce compounds with a high amine index. This parameter is related to the reactivity of the resulting molecule and therefore of the formulated polyols that the molecule forms part of. More reactive Mannich Bases must allow an increase in the shelf life and a saving of catalysts in the polyol component.

Mannich bases that are the product of condensation with primary or secondary aliphatic monoamines are described in the literature with the intention of achieving a higher amine index, but there is no information using the type of amines that are the object of this invention, which present improved properties.

Precedents similar to what is described as the object of this invention can be found in the field of epoxy resin hardeners. They disclose the production of Mannich bases of the same type based on phenol, formol and primary or secondary diamines, but they are not used as polyols for polyurethanes since they do not contain hydroxyl groups and their reactivity to isocyanates is too high. However, it has been observed that all attempts to raise the amine index in non-alkoxylated Mannich bases have so far resulted in compositions that are not stable and that tend to gel.

The authors of the present invention propose new polyols that can also be produced by condensation using the Mannich reaction and adapted to constitute the polyol component of rigid polyurethane foam formulations. These

new polyols are produced by performing the Mannich reaction using compounds with amine groups that have not yet been used, making it possible to have greater nitrogen equivalents per molecule (amine indices) than those described in the prior art and which do not present the above-described problems. The new Mannich bases with a high amine index are non- alkoxylated, i.e. their structure does not include ethylene oxide or propylene oxide. Furthermore, said new polyols are stable, they present an improved reaction to fire, they make it possible to save catalysts in polyurethane foam formulations in which they are used as essential components and they make it possible to increase the shelf life of the formulations.

Moreover, the polyols described by the inventors can be used to form part of formulated polyols that, by reaction with a polyisocyanate, will give rise to spray application rigid polyurethane foams.

Explanation of the invention

In order to overcome the problems posed in the prior art, the object of the present invention is non-alkoxylated hydroxylated Mannich bases that can be produced by condensation of at least one phenolic derivative and at least one aldehyde with a mixture of: a) mono or dialkanolamines; and b) type I aliphatic diamines containing a tertiary amino group and a primary amino group, wherein R ₁ and R ₂ represent C1-C4 alkyl chains and n takes values of 1 to 3, or type Il aliphatic diamines containing a tertiary amino group and a secondary amino group, wherein R ₃ is hydrogen, methyl or ethyl and R ₄ is hydrogen, methyl or ethyl.

Type I Type Il

According to another characteristic of the Mannich bases according to the invention, the R ₁ and R ₂ groups in the type I diamine are equal and are preferably methyl.

Also, variable n is preferably equal to 2.

The type I aliphatic diamine can therefore have tertiary amino groups of the dimethylamine type or of the diethylamine, dipropylamine or dibutylamine type, preferably dimethylamine and the intermediate alkyl chain will be of the ethyl, propyl or butyl type, preferably propyl.

Another aliphatic diamine that has the type I structure is diethylaminopropylamine.

According to the characteristics of the invention, the type Il aliphatic diamine is an aliphatic diamine containing a tertiary amino group and a secondary amino group in the same molecule. In this structure R ₃ is selected from hydrogen, methyl or ethyl and R ₄ is selected from hydrogen, methyl or ethyl.

One of the preferred type Il aliphatic diamines is imidazole.

Other type Il aliphatic diamines that can be used are 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole.

The Mannich bases according to the invention are also characterised in that they correspond to condensates with a hydroxyl index of between 300 and 600 mg KOH/g.

The Mannich bases according to the invention are also characterised in that they have an amine index of between 4.00 and 8.00 meq KOH/g.

According to another characteristic of the invention, the Mannich bases are produced by condensation of at least one phenolic derivative and at least one aldehyde with a mixture of: type I type Il aliphatic diamines with mono or dialkanolamines, wherein the phenolic derivative is phenol. Another object of the invention is a Mannich base that can be produced by condensation of nonylphenol with at least one aldehyde and a mixture of diamines containing a tertiary amino group and a primary (type I) or secondary (type II) amino group with mono or dialkanolamines.

According to another characteristic of the invention, the aldehyde used for the condensation reaction is formaldehyde, also known as formol.

Diethanolamine is preferably selected as the dialkanolamine.

Another object of the present invention is a formulated polyol comprising at least one polyol compound corresponding to a hydroxylated Mannich base that can be produced by condensation of at least one phenolic derivative and at least one aldehyde with a mixture of aliphatic diamines containing a tertiary

amino group and a primary (type I) amino group or aliphatic diamines containing a secondary (type II) tertiary amino group and mono or dialkanolamines, wherein said resulting condensates have a hydroxy! index of between 300 and 600 mg KOH/g and an amine index of between 4.00 and 8.00 meq KOH/g.

The proportion of hydroxy Ia ted Mannich base is preferably between 5% and 60 % by weight in relation to the total weight of the composition; and more preferably between 15% and 25%.

The formulated polyol or composition comprising at least one polyol compound according to the invention is also characterised in that it comprises a polymer independently selected from at least one polyether or at least one polyester or a mixture of the two, at least one compound with flame retardant properties, at least one surfactant agent, at least one foaming catalyst, at least one gelling catalyst, at least one foaming agent and water. Another object of the invention consists of a polyurethane system or formulation to produce rigid polyurethane foams comprising a polyisocyanate component and a formulated polyol component, wherein said formulated polyol component corresponds to a composition comprising at least one polyol compound that is a hydroxylated Mannich base that can be produced by condensation of mono or dialkanolamines with at least one phenolic derivative and at least one aldehyde with a mixture of aliphatic diamines containing a tertiary amino group and a primary (type I) amino group, or aliphatic diamines containing a tertiary amino group and a secondary (type II) amino group; and wherein said resulting condensates have a hydroxyl index of between 300 and 600 mg KOH/g and an amine index of between 4.00 and 8.00 meq KOH/g.

The formulation for rigid polyurethane foams according to the invention is also characterised in that it comprises a polyol component containing a hydroxylated Mannich base that can be produced by condensation of at least one phenolic derivative and at least one aldehyde with a mixture of mono or dialkanolamines with aliphatic diamines containing a tertiary amino group and a primary (type I) amino group or aliphatic diamines containing a tertiary amino group and a secondary (type II) amino group; a polymer independently selected from at least one polyether or at least one polyester or a mixture of the two; at least one compound with flame retardant properties; at least one surfactant agent; at least one foaming catalyst; at least one gelling catalyst; at least one

foaming agent and water.

The formulation for rigid polyurethane foams according to the invention is also characterised in that it is suitable for spray application.

Detailed description of the invention

By way of non-limiting, non-restrictive examples, a description follows of the procedures and apparatus used for synthesising the new hydroxylated Mannich bases that can be produced by condensation of at least one phenolic derivative and at least one aldehyde with a mixture of: a) mono or dialkanolamines; and b) type I aliphatic diamines containing a tertiary amino group and a primary amino group, wherein R ₁ and R ₂ represent C1-C4 alkyl chains and n takes values of 1 to 3, or type Il aliphatic diamines containing a tertiary amino group and a secondary amino group, wherein R ₃ is hydrogen, methyl or ethyl and R ₄ is hydrogen, methyl or ethyl.

EXAMPLES OF SYNTHESIS OF NEW MANNICH BASES EXAMPLE 1

558 g of nonylphenol, 2259 g of dimethylaminopropylamine and 373 g of diethanolamine were mixed in a 2-litre spherical reactor, and the reactor and its contents were then cooled to 30° C using cold water. Then 609 g of a 30 % formaldehyde solution was slowly added, stirring vigorously and endeavouring not to let the temperature exceed 45° C, cooling the reactor when necessary using an ice-water bath. Once the solution had been added (after approximately 1 hour), it was kept at room temperature (25° C) for 1 hour, after which the temperature was increased to 95-100° C and kept at that temperature for 4 hours.

Vacuum was then applied to the system, gradually increasing it until a pressure of less than 10 mbar was reached after 4 hours 30 minutes. These conditions were maintained until no boiling was observed in the condensate and all the water had gone. An orange-coloured product was thus obtained, to which 420 g of tris(chloropropyl)phosphate (TCPP) was added once it had been cooled to 50° C. This was added at a temperature of less than 50° C, stirring the mixture constantly for half an hour. With this procedure, a product was

obtained with a viscosity of 10500 mPa.s, a hydroxy! index of 391 and an amine index of 4.4 meq KOH/g.

EξXAMPLE 2 176 g of 90 % phenol, 172 g of dimethylaminopropylamine and 247 g of diethanolamine were mixed in a 1 -litre spherical reactor, and the reactor and its contents were then cooled to 30° C using cold water. Then 404 g of a 30% formaldehyde solution was slowly added, stirring vigorously and endeavouring not to let the temperature exceed 45° C, cooling the reactor if necessary using an ice-water bath. Once the solution had been added (after approximately 1 hour), it was kept at room temperature (25° C) for 1 hour, after which the temperature was increased to 95-100° C and kept at that temperature for 4 hours.

Vacuum was then applied to the system, gradually increasing it until a pressure of less than 10 mbar was reached after 4 hours 30 minutes. These conditions were maintained until no boiling was observed in the condensate and all the water had gone. An orange-coloured product was thus obtained, to which 208 g of tris(chloropropyl)phosphate (TCPP) was added once it had been cooled to 50° C. This was added at a temperature of less than 50° C, stirring the mixture constantly for half an hour. With this procedure, a product was obtained with a viscosity of 17500 mPa.s, a hydroxyl index of 573 and an amine index of 6.4 meq KOH/g.

Using procedures and materials such as those described in Examples 1 and 2 above it is possible to produce Mannich bases according to the invention, which present a hydroxyl index of between 300 and 600 mg KOH/g and an amine index of between 4.00 and 8.00 meq KOH/g.

Mannich bases produced by condensation of at least one phenolic derivative and an aldehyde with diamines and with dialkanolamines or monoalkanolamines according to the invention are applicable to compositions comprising at least one polyol compound in a suitable solvent or matrix, these compositions constituting the so-called polyol component of rigid polyurethane foam systems or formulations, wherein a polyol component is reacted with a polymer component with isocyanate groups (polyisocyanate) to produce the polyurethane with the desired characteristics.

POLYOL COMPOSITIONS ADAPTED FOR RIGID POLYURETHANE FOAM

FORMULATIONS

EXAMPLE 3: Polyol compositions (polyol component) adapted for use in formulations for spray application rigid polyurethane foams.

Table 1 below shows two compositions comprising at least one polyol compound, which have been used as the polyol component in formulations for rigid polyurethane foams. Specifically, the physical parameters of foams that can be produced from a commercial product by Synthesia Espaήola, S.A. are compared with the physical parameters obtained using a polyol component comprising a new Mannich Base according to the invention. Therefore, the polyol component or composition with formulated polyol referred to as number 1 in Table 1 contains a Mannich base type polyol with a hydroxyl index of 490 mg KOH/g and an amine index of 3.15 meq KOH/g (Synthanol MT-480, commercial product by Synthesia Espanola). The formulated polyol referred to as number 2 contains the product described in Example 1. Both compositions (1 and 2) also contain a glycerine-initiated propoxylated polyether with a hydroxyl index of 380 mg KOH/g (e.g. Voranol CP-450 by The Dow Chemical Company), a flame retardant (tris(chloropropyl) phosphate, TCPP), a standard silicone surfactant to stabilise rigid polyurethane foam (e.g. Tegostab B-8453, by Degussa), foaming catalysts (aromatic or aliphatic tertiary amines: pentamethyl diethylene triamine (PMDTA), dimethyl cyclohexylamine (DMCHA) and dimethyl benzylamine (DMBA)), a gelling catalyst (tin dibutyldilaureate), a hydrofluorocarbon (365mfc/227ea) and water.

Table 1 : Compositions comprising at least one polyol that is a Mannich Base and properties of the polyurethaπe foams produced by reacting said compositions with a polyisocyanate compound.

Components 1 2

Synthanol MT-480 52.20 -

Mannich base example 1 ^a 53.00

Propoxylated polyether 10.00 10.00

TCPP 17.00 18.00

Silicone surfactant 1.50 1.50

PMDTA 0.6

DMCHA 0.5

DMBA 0.6 _

Tin dibutyldilaureate 0.1 _

365mfc/227ea (HFC mixture) 16.0 16.0

Water 1.50 1.50

Viscosity at 23° C (mPa-s) 320 280

Creaming time (sec) ^b 2.0 1.3

Gelling time (sec) ^b 5.4 3.5

Free foam density (Kg/m3) ^b 40.5 42.0

Appearance of foam OK OK

Applied density (Kg/m ³ ) ^b 42.4 43.0

-2O ⁰ C -1.0 -1.5

Dimensional stability (%vol.) ^b 8O ⁰ C -1.0 -1.3

Resistance to compression Perp. 265 275

(Kpa) ^b Paral. 160 150

Initial heat conductivity (mW/m.K) ^b 20.9 21.1

Reaction to fire (Euroclass)" E E

Produced as described in example 1. ^b Parameters calculated in accordance with the UNE 92120-1 :1998 guideline and its amendment UNE 92120-1 :1998/1 M:2003. The quantities shown in table 1 correspond to weight percentages in relation to the total weight of the polyol composition or polyol component.

Specifically, to achieve values of the comparative physical parameters listed in Table 1 tests were performed on spray application rigid polyurethane foams, using a Gusmer H-2000-E type foam machine, a Gusmer D type spray gun and a 62 type mixing chamber. The tests were carried out with a hose temperature of 45° C at a pressure of 70 to 75 bars. A fibre cement substrate was used.

The polyisocyanate used was polymeric MDI (methylenediphenyldiisocyanate) with an NCO index of 30-32 and a viscosity of 200-300 mPa.s. It can be deduced from Table 1 that higher reactivity results (creaming and gelling times) are achieved with polyol component 2, which comprises a Mannich Base according to the invention (Example 1 ) than those achieved with a standard polyol (polyol component 1) without the need for the reaction mixture to include foaming or gelling catalysts. These results show the greater activity of the Mannich Base described in the invention than the standard non- alkoxylated Mannich bases described in the prior art.

EXAMPLE 4: Polyol compositions (polyol component) adapted for use in formulations for spray application rigid polyurethane foams for standard wall insulation systems.

Table 2 shows other compositions comprising at least one polyol compound, which have been used as the polyol component in rigid polyurethane foam formulations for application as wall insulation. Specifically, the physical parameters of foams that can be produced from the same commercial product by Synthesia Espanola, S.A. as in Example 3 are compared with the physical parameters obtained by using compositions comprising the same Mannich Base according to the invention but with different concentrations to other normal compounds in polyol components for rigid polyurethane foams. The formulated polyol component referred to as number 3 contains a

Mannich base type polyol with a hydroxyl index of 490 mg KOH/g and an amine index of 3.15 meq KOH/g (Synthanol MT-480, commercial product by Synthesia Espanola). Formulated polyol components such as 4 and 5 contain the product described in Example 1. The aforementioned formulated polyols also contain a PET-initiated aromatic polyester (polyethylene terephthalate) with a hydroxyl

index of 240 mg KOH/g (Hoopol F-1394, commercial product by Synthesis Espa ^ή ola), a glycerine-initiated propoxylated polyether with a hydroxy! index of 380 mg KOH/g (e.g. Voranol CP-450 by The Dow Chemical Company), a flame retardant (tris(chloropropyl) phosphate, TCPP), a Standard silicone surfactant to stabilise rigid polyurethane foam (e.g. LK 443E, by Air Products), foaming catalysts (aromatic or aliphatic tertiary amines: pentamethyl diethylene triamine (PMDTA), dimethyl cyclohexylamine (DMCHA) and dimethyl benzylamine (DMBA)), a gelling catalyst (tin dibutyldilaureate), a hydrofluorocarbon (245fa) and water. Table 2: Compositions comprising at least one polyol that is a Mannich

Base and properties of the polyurethane foams produced by reacting said compositions with a polyisocyanate compound, which are suitable for spray application.

Component 3 4 5

Synthanol MT-480 20.0 - -

Mannich base example 1 * 20.0 20.0

Hoopol F-1394 34.7 34.7 35.9

Propoxylated polyether 11.0 11.0 11.0

TCPP 15.9 15.9 15.9

Silicone surfactant 1.0 1.0 1.0

PMDTA 1.3 1.3 0.9

DMCHA 1.3 1.3 0.9

DMBA 1.3 1.3 0.9

Water 2.5 2.5 2.5

245fa(HFC) 11.0 11.0 11.0

Viscosity at 23° C (mPa-s) 410 372 360

Creaming time (sec) ^b 2.3 1.8 2.1

Gelling time (sec) ^b 8.0 4.7 6.9

Free density (Kg/m3) ^b 29.7 30.6 31.0

10 days at 40° C

Creaming time (sec) ^b 3.5 3.1 3.5

Gelling time (sec) ^b 12.2 8.0 11.5

Free density (Kg/m3) ^b 31.7 31.3 31.5

20 days at 40° C

Creaming time (sec)" 3.7 3.2 3.5

Gelling time (sec) ^b 15.1 8.8 13.9

Free density (Kg/m3) ^b 32.0 31.9 32.4

Produced as described in example 1. ^b Parameters calculated in accordance with the UNE 92120-1 :1998 guideline and its amendment UNE 92120-1:1998/1 M:2003. The quantities shown in Table 2 correspond to weight percentages in relation to the total weight of the polyol composition or polyol component.

These compositions differ from those used in Example 3, in which new polyols (Mannich bases) were compared with a standard product, as can be observed in terms of the quantity and type of foaming agent (HFC) and water used.

It can be deduced from Table 2 that a higher reactivity is achieved with polyol component 4 than that observed in the standard formulation (polyol component 3) when identical quantities of catalysts are used. This higher reactivity is retained after the samples have been aged for 10 and 20 days at 40° C (it is normal practice to simulate the long-term reactivity of polyol components, for 1.5 and 3 months, by aging the samples under accelerated conditions for 10 and 20 days at a temperature of 40° C). The system's shelf life is established on the basis of its loss of reactivity (slower creaming and gelling times) and it is therefore considered that when the creaming and gelling times are longer than 4 and 15 seconds, respectively, the polyol is no longer suitable for spray application and its shelf life has expired. On this basis, the shelf life of standard polyol component 3 would be 3 months, whereas for polyol component 4, containing a new Mannich Base as disclosed in the present invention, it would clearly be longer because after 20 days at 40° C (simulating 3 months in atmospheric conditions) the reactivity is very much higher and it remains far from the reference values specified above for considering that the shelf life of a polyol has expired.

Moreover, polyol component 5, which contains a new Mannich Base as disclosed in the present invention, presents levels of catalysts that are 30% lower than the standard polyol component 3. In this case the reactivity after 10 and 20 days is very similar, as is the shelf life. It has therefore been shown that it is possible to reduce the quantity of catalysts in the polyol component for a similar shelf life.

In all the polyol compositions or polyol components according to the invention, the proportion of Mannich base is between 5% and 60% by weight, preferably within a range of between 15% and 25% by weight.

Therefore, the advantages of the new non-alkoxylated hydroxylated Mannich bases with a higher amine index as disclosed in the present invention are as follows: 1 ) Higher reactivity, meaning by this lower (faster) creaming and gelling times than those observed when standard Mannich bases are used.

2) Increase in the shelf life.

3) Reduction in the concentration of catalysts in standard formulations for a similar shelf life to that currently presented by standard polyol components.