Polyester polyol and polyurethane produced therefrom

Abstract

The present invention relates to a polyester polyol produced from an acid component containing at least one of pure isophthalic acid (PIA) and phthalic anhydride (PA) and an alcohol component represented by the following Chemical Formula 1, and a polyurethane produced from the polyester polyol: [Formula 1] JPEG2023550989000009.jpg19139L3 is a linear or branched alkylene group having 2 to 6 carbon atoms, which may or may not be substituted with a hydroxy group; or a linear or branched ether group having 2 to 6 carbon atoms, which may or may not be substituted with a hydroxy group. The polyester polyol according to the present invention has excellent storage stability and compatibility, and polyurethanes produced using the polyester polyol have excellent flame retardancy and dimensional stability.

Description

[Technical Field]

[0001] The present invention relates to a polyester polyol for producing a semi-flammable rigid polyurethane and to a polyurethane produced therefrom. [Background technology]

[0002] As energy conservation policies to reduce greenhouse gas emissions become stronger worldwide, the role of insulation materials is becoming increasingly important among building materials. Furthermore, a series of building fires has led to increased interest in materials that offer both insulation and flame retardancy. Polyurethane foam has superior insulation properties compared to other materials (EPS, XPS, Rockwool), and has recently been attracting much attention as an insulation material. However, its use has been somewhat stagnant due to concerns about its flame retardancy.

[0003] Among polyols, which are essential components of polyurethane, polyether polyols and polyester polyols are known to be the most common polyols. These polyols have a significant impact on the properties of the polyurethane or polyurethane foam to be produced.

[0004] Generally, polyols with high molecular weight and low functionality are used to produce soft urethane foams, while polyols with low molecular weight and high functionality are used to produce rigid urethane foams.

[0005] Polyurethane foam, especially rigid polyurethane foam, is used in a variety of fields, and the required physical properties vary depending on the field of application. Among these, when used as an insulating material for interior and exterior building materials, flame retardancy, dimensional stability, moldability, insulating properties, and environmental friendliness are particularly required.

[0006] The commonly used polyester polyol with a phthalic anhydride (PA) backbone structure was used as the main resin for rigid polyurethane foam (PUR / PIR), but it had poor flame retardancy, so recently a pure terephthalic acid (PTA) backbone was developed. However, when using polyester polyol with a PTA structure alone, the flame retardancy of the polyurethane produced from this raw material is ensured, but the high crystallinity of the polyester polyol causes problems such as solidification at room temperature, resulting in poor storage stability.

[0007] To overcome these shortcomings, PTA / PA-based products have been developed, but if flame retardancy regulations become stricter, it is likely that market adoption will be difficult.Furthermore, products based on pure isophthalic acid (PIA) have excellent flame retardancy, but have problems with compatibility and increased viscosity. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Korean Patent Publication No. 2012-0027422 Summary of the Invention [Problem to be solved by the invention]

[0009] In order to solve the above-mentioned problems, the present invention aims to provide a polyester polyol having low viscosity, excellent storage stability, and excellent compatibility, and a polyurethane produced using the polyester polyol and having excellent flame retardancy. [Means for solving the problem]

[0010] The present invention relates to an acid component containing at least one of pure isophthalic acid (PIA) and phthalic anhydride (PA); and Provided is a polyester polyol produced from an alcohol component represented by the following chemical formula 1: [ka]

[0011] L3 is a linear or branched alkylene group having 2 to 6 carbon atoms which may or may not be substituted with a hydroxy group; or a linear or branched ether group having 2 to 6 carbon atoms which may or may not be substituted with a hydroxy group.

[0012] The present invention also provides a polyurethane prepared by reacting the polyester polyol with one or more compounds containing two or more isocyanate groups. [Effects of the Invention]

[0013] According to the present invention, a polyester polyol having excellent storage stability, low viscosity, and excellent reactivity with isocyanate can be provided. In addition, polyurethanes produced using the polyester polyol according to the present invention have excellent flame retardancy and dimensional stability. BEST MODE FOR CARRYING OUT THE INVENTION

[0014] In the present invention, an acid component selected from the group consisting of pure isophthalic acid (PIA) and phthalic anhydride (PA) and an alcohol component represented by the following chemical formula 1 are used to produce polyester polyol: [ka]

[0015] L3 is a linear or branched alkylene group having 2 to 6 carbon atoms which may or may not be substituted with a hydroxy group; or a linear or branched ether group having 2 to 6 carbon atoms which may or may not be substituted with a hydroxy group.

[0016] The present invention provides aromatic polyester polyols with excellent compatibility, low viscosity, and storage stability by specifying the type and mixing ratio of acid components and using specific alcohol components, thereby providing aromatic polyester polyols with optimal base number (OH value) and acid value, reduced crystallinity, and excellent reactivity with isocyanates through low viscosity control (increased low molecular weight distribution).The present invention also provides flame-retardant polyurethanes produced therefrom.

[0017] In the present invention, isophthalic acid (PIA) or phthalic anhydride (PA) can be used as the acid component, and these can be used alone or in combination. In particular, the present invention provides a polyol containing PIA as the acid component, and in this case, PIA is preferably contained in a proportion of 80 to 100 mol %.

[0018] In one embodiment of the present specification, the polyester polyol represented by Chemical Formula 1 is composed of an isophthalic acid (PIA)-based backbone instead of a phthalic anhydride (PA)-based or purified terephthalic acid (PTA)-based backbone. Compared to a PTA-based backbone, PIA has less steric hindrance and is more reactive with isocyanates, and it can also enhance the flame retardancy of the resulting polyurethane. Therefore, the present invention proposes that PIA be included as the acid component of the polyester polyol, and that the PIA be included in a proportion of 80 to 100 mol% of the acid component to achieve the desired effect.

[0019] In addition, when a certain amount of PA is mixed as an acid component, it is possible to provide a quasi-nonflammable aromatic polyester polyol with excellent reactivity with isocyanates through reduced crystallinity and low viscosity control (increased low molecular weight distribution).

[0020] In the present invention, the alcohol component represented by Chemical Formula 1 can be monoethyl glycol, diethylene glycol, neopentyl glycol, methylpropanediol, or trimethylolpropane, and in particular, neopentyl glycol (NPG) or diethylene glycol (DEG) can be used.

[0021] NPG has a bulky structure, which increases solubility. Its short chain methyl group enhances flame retardancy and compatibility compared to DEG through van der Waals interactions. Furthermore, NPG contains tertiary carbon atoms, which provide relatively high thermal stability and reduce crystallinity. Therefore, one embodiment of the present invention proposes using NPG as the alcohol component of polyester polyol, together with diethylene glycol (DEG).

[0022] When NPG and DEG are used together as the alcohol components, the mixing ratio is preferably in the range of 1:2 to 1:20 in terms of molar ratio in order to obtain the effect of using NPG.

[0023] The polyester polyol of the present invention is prepared by mixing the acid component and the alcohol component in a ratio of 1.0:1.4 to 2.0 mol. The reaction of the acid component and the alcohol component is carried out using a catalyst such as butylstannoic acid, butyltin tris-2-ethylhexanoate, or tertabutyl titanate at a temperature of 170 to 240°C under atmospheric pressure for 7 to 12 hours.

[0024] The polyester polyol of the present invention preferably has a weight-average molecular weight of 300 g / mol to 3,000 g / mol from the viewpoints of storage stability and flame retardancy of polyurethanes produced using the same. Specifically, if the weight-average molecular weight of the polyester polyol is less than 300 g / mol, production is difficult, while if the weight-average molecular weight exceeds 3,000 g / mol, the storage stability and urethane reactivity of the polyester polyol decrease, and the flame retardancy of the polyurethane deteriorates.

[0025] The polyester polyol of the present invention uses PIA or PA as the acid component, and particularly contains PIA, and uses DEG or a mixture of DEG and NPG as the alcohol component, thereby achieving low viscosity control, a low molecular weight distribution, and excellent reactivity with isocyanates, which is advantageous from the perspective of polyurethane production.

[0026] The present invention provides polyurethanes produced by reacting the polyester polyols with one or more compounds containing two or more isocyanate groups. The polyurethanes can be produced by commonly known techniques, typically involving the reaction of an isocyanate component and a polyol component in the presence of a catalyst and a blowing agent.

[0027] The one or more compounds containing two or more isocyanate groups are compounds containing two or more isocyanate groups (-N=C=O), such as 1,12-dodecane diisocyanate, 2-ethyltetramethylene 1,4-diisocyanate, 2-methylpentamethylene 1,5-diisocyanate, tetramethylene 1,4-diisocyanate, hexamethylene 1,6-diisocyanate; cyclohexane 1,3-diisocyanate, cyclohexane 1,4-diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanate, and the like. Anatomethylcyclohexane (IPDI), 2,4-hexahydrotolylene diisocyanate, 2,6-hexahydrotolylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane Diisocyanate, polyphenylpolymethylene polyisocyanate, 1,5-naphthylene diisocyanate (NDI), 3,3'-dimethylbiphenyl diisocyanate, 1,2-diphenylethane diisocyanate, p-phenylene diisocyanate (PPDI), trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, 2-methylpentamethylene 1,5-diisocyanate isocyanate, 2-ethylbutylene 1,4-diisocyanate, pentamethylene 1,5-diisocyanate, butylene 1,4-diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (isophorone diisocyanate, IPDI), 1,4-bis(isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane (HXDI), 1,4-cyclohexane diisocyanate, isomers thereof, or mixtures thereof.

[0028] In one embodiment of the present invention, further additives may be added as necessary during the preparation of the polyurethane, including, but not limited to, commonly used additives such as blowing agents, flame retardants, foam stabilizers, catalysts, surfactants, foam stabilizers, cell regulators, fillers, dyes, pigments, and hydrolysis inhibitors.

[0029] As used herein, the blowing agent may include, but is not limited to, water, carboxylic acids, fluorocarbon blowing agents, carbon dioxide, and hydrocarbon blowing agents such as straight or branched chain alkane hydrocarbons.

[0030] The flame retardant used herein may be a commonly used flame retardant, such as brominated esters, brominated ethers (Ixol), or brominated alcohols, such as dibromoneopentyl alcohol, tribromoneopentyl alcohol, and PHT-4-diol, as well as chlorinated phosphates, such as tris(2-chloroethyl)phosphate, tris(2-chloropropyl)phosphate (TCPP), tris(1,3-dichloropropyl)phosphate, tricresyl phosphate, tris(2,3-dibromopropyl)phosphate, tetrakis(2-chloroethyl)ethylenediphosphate, dimethylmethanephosphate, diethyldiethanolaminomethylphosphate, and commercially available halogenated flame retardant polyols. Additional phosphates or phosphonates may be used as liquid flame retardants, such as, but not limited to, diethylethanephosphate (DEEP), triethylphosphate (TEP), dimethylpropylphosphate (DMPP), or diphenylcresylphosphate (DPK).

[0031] In this specification, the foam stabilizer includes, but is not limited to, silicone foam stabilizers, nonionic foam stabilizers, non-silicone foam stabilizers, and the like, specifically, foam stabilizers such as dinonylphenol, methyl glucoside, methyl propanediol, vinyl ether maleic acid, and Si-copolymers.

[0032] The catalyst used herein may be a commonly used catalyst, such as triethylamine, tributylamine, dimethylbenzylamine, dicyclohexylmethylamine, dimethylcyclohexylamine, N,N,N',N'-tetramethyldiaminodiethyl ether, bis(dimethylaminopropyl)urea, N-methylmorpholine, N-ethylmorpholine, N-cyclohexylmorpholine, N,N,N',N'-tetramethylethylenediamine, N,N,N,N-tetramethylbutanediamine, N,N,N,N-tetramethylhexane-1,6-diamine, pentamethyldiethylenetriamine, bis(2-dimethylaminoethyl)ether, dimethylpiperazine, N-dimethylaminoethylpiperidine, 1,2-dimethylimidazole, 1-azabicyclo[2.2. 0]octane, 1,4-diazabicyclo[2.2.2]octane (Dabco), triethanolamine, triisopropanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, dimethylaminoethanol, 2-(N,N-dimethylaminoethoxy)ethanol, N,N',N"-tris(dialkylaminoalkyl)hexahydrotriazine, N,N',N"-tris(dimethylaminopropyl)-s-hexahydrotriazine, triethylenediamine, iron(II) chloride, zinc chloride, lead octoate, tin dioctoate, tin diethylhexoate, dibutyltin dilaurate, tetraisopropyl titanate, butylstannoic acid, butyltin chloride dihydroxide, tetrabutyl titanate, and mixtures thereof.

[0033] Polyurethanes produced using polyester polyols according to one embodiment of the present invention have excellent flame retardancy and dimensional stability.

[0034] Hereinafter, the present invention will be described in detail based on examples in order to specifically explain the present invention. However, the examples according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the examples described below. The examples in this specification are provided to more completely explain the present invention to those skilled in the art.

[0035] Comparative Example 1 A 2L reactor equipped with a stirrer, packing column, and stirring bar was charged with 4.6 mol of PA (phthalic anhydride, Sigma-Aldrich), 8.38 mol of DEG (diethylene glycol, Lotte Chemical), and 0.0008 mol of Fascat 4100 (butylstannoic acid, Arkema), and the temperature was raised to 170°C (2 hours). The stirring speed was 200 rpm during the temperature increase, and the ES reaction was carried out for 2 hours. The temperature was then raised to 230°C for 3 hours. After maintaining this for 1 hour, the vacuum was set to 200 mmHg and the reaction was continued for 2 hours, producing a resin with an acid value (mg KOH / g resin) of 0.4 and a hydroxyl value (mg KOH / g resin) of 276.

[0036] Comparative Examples 2 to 5 A resin was produced in the same manner as in Comparative Example 1, except that some of the conditions were changed as shown in Table 1 below.

[0037] Example 1 A 2L reactor equipped with a stirrer, packing column, and stirring bar was charged with 4.6 mol of PIA (pure isophthalic acid, Lotte Chemical), 7.58 mol of DEG (diethylene glycol, Lotte Chemical), 0.84 mol of NPG (neopentyl glycol, LG Chem), and 0.0008 mol of Fascat 4100 (butylstannoic acid, Arkema). The temperature was first raised to 170°C (2 hours). The stirring speed was 200 rpm during the temperature rise process, and the ES reaction was carried out for 2 hours. The temperature was then raised again to 230°C for 3 hours. After maintaining the temperature for 1 hour, the vacuum was set to 200 mmHg and the reaction was continued for 2 hours, producing a resin with an acid value (mg KOH / g resin) of 0.5 and a hydroxyl value (mg KOH / g resin) of 281.

[0038] Examples 2 and 3 A resin was produced in the same manner as in Example 1, except that some of the conditions were changed as shown in Table 1 below.

[0039] [Table 1]

[0040] -PTA (pure terephthalic acid, Lotte Chemical) -Storage safety: The liquid state of the sample was evaluated as follows for 3 months in a warming cabinet at 15°C. X: Gelling or solidification within 2 weeks, or increase in viscosity by 30% or less compared to the initial viscosity △: Gelling or solidification within 2 months, or increase in viscosity by 30% or less compared to the initial viscosity ○: Gelling or solidification within 4 months, or increase in viscosity by 30% or less compared to the initial viscosity ◎: Gells or solidifies within 6 months, or increases in viscosity by 30% or less compared to the initial viscosity Viscosity: A sample at 25°C was evaluated using a Brookfield viscometer with spindle 64. - Compatibility: After blending polyol / water / blowing agent (cyclopentane) / foam stabilizer at room temperature, the liquid phase state was evaluated for 3 months. X: Gells or solidifies within 2 weeks, △: Gells or solidifies within 1.0 month, O: Gells within 2 months, ◎: Viscosity increases by no more than 30% compared to the initial viscosity in 3 months or more -TGA_50% (℃) is the temperature at which the weight loss reaches 50% in a TGA N2 atmosphere.

[0041] Next, polyurethane was prepared from the polyol. 100 g of resin, 10 g of TCPP (flame retardant, Tris(1-chloro-2-propyl)phosphate, Sigma-Aldrich), 1 g of TEGOSTAB® B8462 (foam stabilizer, silicone surfactant, Evonik), 12 g of cyclopentane (blowing agent, Sigma-Aldrich), 3.5 g of Dabco k-15 (catalyst, Evonik), and 1.0 g of DMCHA (catalyst, N,N-dimethylcyclohexylamine, Huntsman) were placed in a 2-L can and mixed with a high-speed mixer to prepare a system polyol.

[0042] [Table 2]

[0043] The -NCO index was calculated in the following manner.

number

[0044] The physical properties of the prepared polyurethane are shown in Table 3 below.

[0045] [Table 3]

[0046] -Total heat release and total smoke generation: Measured using a CONE calorimeter (KS F ISO 5660-1). Total smoke generation was evaluated at X: 150m 2 / m 2 Above, △:100~150m 2 / m 2 , ○: 80~100m 2 / m 2 , ◎:80m 2 / m 2 Shown below. - Water absorption: A 100 x 100 x 25 mm test piece was immersed in 25°C water for 10 seconds, removed, left for 30 seconds, and then weighed to serve as the reference weight. The test piece was then immersed in clean water for 96 hours, and the weight after final water absorption was measured. The water absorption was calculated using the following formula: Water absorption amount (g / 100cm 2 ) = (weight after final water absorption - base weight) / surface area × 100

[0047] The evaluation was indicated as follows: X: 3g or more, △: 1-3g, O: 0.2-1.0g, ⊚: 0.1g or less.

[0048] The polyols of Examples 1 to 3 were excellent in storage stability and compatibility, and the polyurethanes produced therefrom also had excellent flame retardancy. On the other hand, the polyol of Comparative Example 2 exhibited significantly reduced storage stability and compatibility, and Comparative Examples 1, 4, and 5 showed poor results in terms of flame retardancy. Furthermore, the PIA / DEG polyol of Comparative Example 3 had good physical properties such as flame retardancy and moisture absorption rate, but its compatibility with the raw materials used in the system polyol was reduced, making it difficult to use.

[0049] More specifically, the polyols in Comparative Examples 1 to 3 were produced using DEG as the alcohol component and the same amount of other acid components, allowing for a comparison of the effects of different acid components. When PA was used (Comparative Example 1), good storage stability and compatibility were maintained, but flame retardancy was very poor. When PTA was used (Comparative Example 2), storage stability and compatibility were significantly reduced. When PIA was used (Comparative Example 3), compatibility was slightly reduced. However, compared to Example 1, which used NPG as the alcohol component under the same conditions, storage stability and compatibility were also reduced, and total heat release and total smoke generation increased, indicating poor physical properties. That is, when PIA was used alone as the acid component, excellent polyols were obtained when NPG was used as the alcohol component. Furthermore, when Comparative Example 3 was compared with Example 3, which used a mixture of PIA and PA as the acid components, significantly improved storage stability and compatibility were confirmed. That is, when DEG alone was used as the alcohol component, polyols with excellent physical properties were obtained when PIA and PA were used together.

[0050] Next, the polyols of Example 1 and Comparative Example 3 showed the results of changes when PIA was used alone as the acid component and when NPG was mixed in as the alcohol component, and when NPG was mixed in, the storage stability and compatibility were superior to when DEG was used alone.

[0051] The polyols in Example 3 and Comparative Example 5 were prepared by using PA and PIA as acid components at different mixing ratios, and the flame retardancy was poor in Comparative Example 5, in which the amount of PA used was increased.

[0052] Therefore, it was confirmed that by using PIA alone as the acid component, or by using PA and PIA in a certain mixing ratio and DEG or a mixture of DEG and NPG as the alcohol component, as in the polyester polyols according to the examples of the present invention, the storage stability and compatibility of the polyol can be improved, and the flame retardancy and dimensional stability of the polyurethane produced using the same can be improved.

Claims

1. A polyester polyol for producing a flame-retardant polyurethane, which is produced from an acid component containing at least one of isophthalic acid (PIA) and phthalic anhydride (PA), and an alcohol component, The alcohol component contains neopentyl glycol (NPG) and diethylene glycol (DEG), and the NPG:DEG mixing molar ratio is 1:2 to 1:20; The polyester polyol for producing flame-retardant polyurethanes, wherein the molar ratio of PIA to PA in the acid component is 100:0 to 90:

10.

2. A flame retardant polyurethane made from the polyester polyol of claim 1.

Images