JP2013521356A - Method for producing polyurethane rigid foam material - Google Patents

Abstract

The present invention
a) Polyisocyanate
b) a compound having at least two isocyanate group-reactive hydrogen atoms;
c) A method for producing a rigid polyurethane foam comprising a step of reacting in the presence of a foaming agent,
Compound b) having at least two isocyanate group reactive hydrogen atoms is
By using amine b1c) as a catalyst, it is obtained by adding alkylene oxide b1b) to compound (b1a) (hereinafter also referred to as starting material) having an alkylene oxide reactive hydrogen atom, and has a functionality of 2 to 2. And at least one polyether alcohol b1) having a hydroxyl number of 200 to 800 mg-KOH / g.
[Selection figure] None

Description

  The present invention relates to a method for producing a rigid polyurethane foam by reacting a polyisocyanate with a compound having at least two isocyanate group-reactive hydrogen atoms in the presence of a blowing agent.

  Rigid polyurethane foams have been known for a long time and are mainly used in thermal insulation and cold insulation (eg refrigeration equipment), in hot water storage systems, in district heat piping, or in the form of sandwich materials. ing. Review articles on the production and use of rigid polyurethane foams can be found in, for example, Kunststoff-Handbuch, volume 7, Polyurethanes 1st edition 1966, edited by Dr. R. Viewweg and Dr. A. Hochtlen, and 2nd edition 1983, edited by Dr. Gunter Oertel, and 3rd edition 1993, edited by Dr. See Gunter Oeltel, Carl Hanser Verlag, Munich, Vienna.

  The blowing agent used in the production of rigid polyurethane foams has mainly been chlorofluorocarbon (CFC), preferably trichlorofluoromethane. However, these foaming gases have an adverse effect on the environment.

  As an alternative to these CFCs, hydrocarbons, preferably pentane, are the most commonly used. EP-A-42269 describes the use of cyclopentane and / or cyclohexane as blowing agent, if necessary in admixture with other hydrocarbons.

  However, these blowing agents differ from halogenated blowing agents in various ways. These have low affinity for other components of the polyurethane system. For this reason, the component containing a foaming agent will isolate | separate rapidly.

  A large amount of foaming agent cannot be put in these components. Accordingly, foams that are foamed with alkanes are typically more dense than foams that are foamed with CFCs.

  Accordingly, it is necessary to increase the density of the foam without reducing the thermal conductivity or mechanical properties of the polyurethane. When filling a hollow space such as a housing of a refrigerator with a foam, it is necessary to uniformly fill the hollow space. That is, the liquid reactive component needs to flow into all regions of the hollow space. If the foam has insufficient fluidity, a hollow space with a large volume and / or complex shape must be filled with excess foam to ensure a uniform distribution of the foam due to the pressure generated there. There is. The easier the liquid reactive component is filled into the hollow space, the less rigid polyurethane foam is needed to completely fill the hollow space with the foam. As a result, the rigid polyurethane foam in the hollow space has a low density, the weight of the final product, for example, the refrigeration apparatus is reduced, and material saving is possible.

  In this case, the fluidity of the foam refers to the flow behavior of a reactive mixture of polyisocyanate and a compound having at least two isocyanate group reactive hydrogen atoms. Fluidity is usually determined by measuring the distance covered by the reactive mixture. This involves injecting the reaction mixture into a flexible polymer membrane tube (hereinafter referred to as a tube test) or into a standardized long mold (eg, a so-called Bosch lance) and measuring the length of the resulting molded part. Can be done.

  The fluidity of the reaction mixture is usually determined by measuring the flow coefficient. This flow coefficient is a ratio between the minimum packing density and the envelope density when free-foaming is performed, and is determined using a Bosch lance. This minimum packing density is obtained by varying the shot weight and corresponds to the minimum density required to completely fill the Bosch lance with a certain free envelope density.

EP-A-42269

  An object of the present invention is to provide a method for producing a rigid polyurethane foam, which has a high solubility of a polyol component in a hydrocarbon used as a foaming agent. Improvements in processing properties, in particular fluidity, also need to be achieved. In addition, it is necessary to obtain a foam having favorable mechanical properties and low thermal conductivity.

  We have surprisingly found that polyols obtained by adding alkylene oxides to compounds having at least two active hydrogen atoms in the presence of at least one compound having at least one amino group as a catalyst. And found that this purpose is achieved.

  Compounds prepared by adding alkylene oxide to a compound having at least two active hydrogen atoms in the presence of at least one compound having at least one amino group as a catalyst are known.

  US20070203319 and US20070199976 describe polyether alcohols obtained by adding alkylene oxide to starting materials containing compounds that are solid at room temperature using dimethylethanolamine. However, there is no description of polyurethanes obtained using these polyols. In addition, this document does not contain any clues about the properties of these polyols during the production of the foam and the effects on the properties of the foam.

The present invention
a) Polyisocyanate
b) a compound having at least two isocyanate group-reactive hydrogen atoms;
c) A method for producing a rigid polyurethane foam comprising a step of reacting in the presence of a foaming agent,
The compound b) having at least two isocyanate group-reactive hydrogen atoms is converted into a compound (b1a) having an alkylene oxide reactive hydrogen atom (hereinafter also referred to as a starting material) by using amine b1c) as a catalyst. And at least one polyether alcohol b1) obtained by adding alkylene oxide b1b), having a functionality of 2-8 and a hydroxyl number of 200-800 mg-KOH / g. A manufacturing method is provided.

  As component b), polyether alcohol b1) can be used alone.

  Preferably, the polyether alcohol b1) is used in an amount of 10 to 90% by weight, based on the weight of component b).

  Preferably, the compound having at least two alkylene oxide reactive hydrogen atoms used for the production of the polyether alcohol b1) comprises a mixture comprising at least one compound b1ai) which is solid at room temperature. The functionality of compound b1ai) is preferably at least 3, more preferably at least 4, more preferably 3-8, even more preferably 4-8.

  Such compounds b1ai) are known and are often used for the production of polyether alcohols, in particular those used in rigid polyurethane foams. Compound b1ai) is preferably trimethylolpropane, pentaerythritol, glucose, sorbitol, mannitol, sucrose, polyhydric phenol, resole, eg oligomeric condensation products of phenol and formaldehyde, aniline and formaldehyde (MDA) and oligomeric It is selected from the group consisting of condensation products, toluenediamine (TDA), Mannich condensation products of phenol, formaldehyde and dialkanolamine, melamine, and mixtures of at least two of the aforementioned alcohols.

  In one preferred embodiment of the invention, compound b1ai) is selected from the group consisting of sucrose, sorbitol and pentaerythritol, more preferably selected from sucrose or sorbitol. In a particularly preferred embodiment of the invention, b1ai) is sucrose.

  The aromatic amine used as the compounds b1ai) is specifically selected from the group consisting of toluenediamine (TDA), diphenylmethane diisocyanate (MDA) or polymeric MDA (p-MDA). In the case of TDA, the 2,3-isomer and the 3,4-isomer (also called vicinal TDA) are used in particular.

  Useful starting materials further include compounds b1a) having at least two alkylene oxide reactive hydrogen atoms, including at least one compound b1aii) which is liquid at room temperature.

  In a preferred embodiment of the invention, the starting material of component b1) comprises compound b1ai) and compound b1ai) which contain hydrogen atoms reactive with alkylene oxide and are liquid at room temperature. Compound b1iii) may comprise an alcohol or an amine. These have, in particular, hydrogen atoms reactive with 1 to 4, preferably 2 to 4 alkylene oxides. Component b1 aii) includes in particular glycerol, monofunctional alcohols having 1 to 20 carbon atoms, ethylene glycol and its higher homologues, propylene glycol and its higher homologues, ethanolamine, diethanolamine, triethanolamine, etc. It is selected from the group consisting of hydroxyalkylamines and reaction products of these with propylene oxide. Glycerol is particularly used.

  As described above, the alcohols (b1aii) which are liquid at room temperature may further contain a compound having one alkylene oxide reactive hydrogen atom and 1 to 20 carbon atoms. Monofunctional alcohols such as methanol, ethanol, propanol, octanol, and dodecanol are preferred.

  In another embodiment of the invention, the starting material of component b1a) comprises a mixture of at least one room temperature solid amine b1ai) and room temperature liquid alcohol b1ai). As mentioned above, the alcohols b1ai) that are solid at room temperature preferably contain MDA and polymeric MDA.

The alcohol b1aii) which is liquid at room temperature preferably contains ethylene glycol and its higher homologues and propylene glycol and its higher homologues. The concentration of these amine homologues in p-MDA depends on the process conditions. In general, its distribution (mass percent) is as follows:
Bicyclic MDA: 50-80% by mass
Tricyclic MDA: 10 to 25% by mass
Tetracyclic MDA: 5-12% by mass
Five or more ring MDA: 5 to 12% by mass
A preferred p-MDA mixture has the following composition:
Bicyclic MDA: 50% by mass
Tricyclic MDA: 25% by mass
Tetracyclic MDA: 12% by mass
MDA higher than five rings: 13% by mass
Further preferred p-MDA mixtures have the following composition:
Bicyclic MDA: 80% by mass
Tricyclic MDA: 10% by mass
Tetracyclic MDA: 5% by mass
Five or more rings of MDA: 5% by mass

  In a further preferred embodiment of the invention, the starting material of component b1a) comprises a mixture of at least one room temperature solid alcohol (b1ai) and one room temperature liquid alcohol (b1ai). The alcohol (b1ai) that is solid at room temperature preferably contains sugar alcohol, glucose, sorbitol, mannitol, and sucrose, and specifically contains the above-mentioned substances, specifically sucrose. Alcohol that is liquid at room temperature (b1aii) is a monofunctional alcohol having 1 to 20 carbon atoms, ethylene glycol and its higher homologue, propylene glycol and its higher homologue, ethanolamine, diethanolamine, triethanolamine, etc. These hydroxyalkylamines, their homologues obtained from propylene oxide, and glycerol are preferable, and specifically, glycerol is preferably included. The starting material of component b1a) may also contain water. When water is used, the amount is specifically less than 25% by weight, based on the weight of the starting material of component b1).

  The alkylene oxide b1b) preferably comprises propylene oxide, ethylene oxide, butylene oxide, isobutylene oxide, styrene oxide, and mixtures of two or more thereof. Preference is given to using propylene oxide, ethylene oxide or a mixture of propylene oxide and ethylene oxide as alkylene oxide b1b). It is particularly preferred to use propylene oxide as alkylene oxide b1b).

  As mentioned above, catalyst b1c) contains a different amine than component b1aii). The amine may contain primary amines, secondary amines or tertiary amines and may contain aliphatic amines or aromatic amines, especially tertiary amines. In other embodiments, aromatic heterocyclic compounds having at least one nitrogen atom in the ring, preferably having one nitrogen atom, may be involved.

  These amines b1c) are preferably trialkylamines (specifically trimethylamine, triethylamine, tripropylamine, tributylamine), dimethylalkylamines (specifically dimethylethanolamine; dimethylethoxyethanol-amine, dimethyl). Cyclohexylamine, dimethylethylamine, dimethylbutylamine), aromatic amine (specifically, dimethylaniline, dimethylaminopyridine, dimethylbenzylamine, pyridine), imidazole (specifically, imidazole, N-methylimidazole, 2- Methylimidazole, 4-methylimidazole, 5-methylimidazole, 2-ethyl-4-methylimidazole, 2,4-dimethylimidazole, 1-hydroxypropylimidazole, 2, , 5-trimethylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, N-phenylimidazole, 2-phenylimidazole, 4-phenylimidazole), guanidine, alkylated guanidine (specifically 1,1 , 3,3-tetramethylguanidine), 7-methyl-1,5,7-triazabicyclo [4.4.0] dec-5-ene, amidine (specifically, 1,5-diazo-bicyclo). [4.3.0] non-5-ene, 1,5-diazabicyclo [5.4.0] undec-7-ene).

  It is also possible to use mixtures of at least two amines mentioned as catalysts.

  In one preferred embodiment of the invention, catalyst b1c) is dimethylethanolamine.

  In one preferred embodiment of the invention, catalyst b1c) is imidazole.

  This amine b1c) is used in an amount of 0.01-5.0% by weight, preferably 0.05-3.0%, more preferably 0.1-1.0%, based on the total batch. Is preferred. The entire batch is assumed to be the amount of all starting compounds used in the production of the polyether alcohol b1).

  In order to produce the polyether alcohol b1), the components of the starting material mixtures b1a) and b1c) are usually charged into the reactor and mixed with each other. The mixture is then inactivated therein. Thereafter, alkylene oxide is charged.

  The alkylene oxide addition reaction is preferably carried out at a temperature of 90 to 150 ° C. and a pressure of 0.1 to 8 bar. In order to complete the reaction of the alkylene oxide, a post-reaction phase usually follows after the introduction of the alkylene oxide.

  Usually, after completion | finish of injection | emission of alkylene oxide, a post-reaction period is performed and reaction of alkylene oxide is completed. This is followed by the post reaction phase if necessary. Usually, this is followed by distillation for removal of volatile substances, preferably under reduced pressure.

  Amine catalyst b1c) may remain in the polyether alcohol. This eliminates the need for catalyst removal when using alkali metal oxides and hydroxides, which simplifies the production process. This improves the space time yield. A filter cake is formed when the salt is removed by filtration. The loss of polyol in the filter cake is usually a few percent. Improvement of space time yield and prevention of filtration loss lead to lower production costs.

  Combinations of alkali metal hydroxide catalysts and amine-based catalysts are also useful. This can be used in particular for the production of low hydroxyl number polyols. The resulting product can be worked up in the same manner as polyols with alkali metal hydroxide catalysts. Alternatively, these can be treated by performing only the neutralization step using acid. In this case, it is preferable to use a carboxylic acid such as lactic acid, acetic acid or 2-ethylhexanoic acid.

  The amine catalyst b1c) may be alkoxylated during the reaction. Thus, these alkoxylated amines have a higher molecular weight and exhibit less volatility in subsequent products. Due to the remaining self-reactivity of the alkoxylated amine catalyst, it is incorporated into the polymer structure upon reaction with the isocyanate downstream. Since the tertiary amine formed is self-reactive, the polyol can be given self-reactivity useful for use in a specific application.

  Without being bound by any particular theory, it is believed that polyether alcohols obtained using amines as catalysts have a different structure from that of polyether alcohols obtained using other catalysts. This different molecular structure is an advantage in the production of polyurethane.

Therefore, the polyol of the present invention is used in a polyurethane application, particularly in a method for producing a polyurethane foam.
Has clear advantages.

  As mentioned above, the polyether alcohol b1) is used in the production of polyurethane.

The starting materials used for this are described more specifically as follows:
Possible organic polyisocyanates a) are preferably polyfunctional aromatic isocyanates.

  Specific examples include: 2,4- and 2,6-tolylene diisocyanate (TDI) and its isomer mixtures, 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanate (MDI) and its Isomer mixtures, 4,4'- and 2,4'-diphenylmethane diisocyanate, and in the production of rigid polyurethane foams, in particular 4,4'-, 2,4'- and 2,2'- A mixture (crude MDI) of diphenylmethane diisocyanate and polyphenylpolymethylene polyisocyanate can be mentioned.

  The polyether alcohol of the present invention is usually used as a mixture with another compound having at least two isocyanate group-reactive hydrogen atoms.

  Compounds having at least two isocyanate-reactive hydrogen atoms that are useful in combination with the polyether alcohol b1) used in the present invention have an OH number in the range of 100 to 1200 mg-KOH / g, in particular. Polyether alcohol and / or polyester alcohol are included.

  The polyester alcohol used in combination with the polyether alcohol b1) usually has 2 to 12 carbon atoms, preferably a multifunctional alcohol having 2 to 6 carbon atoms, preferably a diol and 2 to 12 carbon atoms. Polyfunctional carboxylic acids having the following carbon atoms (for example, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedioic acid, maleic acid, fumaric acid, preferably phthalic acid, isophthalic acid, terephthalic acid Acid, naphthalenedicarboxylic acid isomer mixture).

  The functionality of the polyether alcohol used in combination with the polyether alcohol b1) is usually 2-8, specifically 3-8.

  It is particularly preferred to use polyether alcohols prepared by known methods, for example using polyether alcohols prepared by anionic polymerization of alkylene oxides in the presence of a catalyst (preferably an alkali metal hydroxide). .

  The alkylene oxide used is mostly ethylene oxide and / or propylene oxide, preferably pure 1,2-propylene oxide.

  The starting molecules used are in particular compounds having at least 3, preferably 4 to 8 hydroxyl groups in the molecule or having at least 2 primary amino groups.

  Starting molecules having at least 3, preferably 4-8, hydroxyl groups in the molecule include trimethylolpropane, glycerol, pentaerythritol, sugar compounds (eg, glucose, sorbitol, mannitol, sucrose), polyvalent Preference is given to using phenols, resols, such as phenol-formaldehyde oligomeric condensation products, aniline-formaldehyde (MDA) condensation products, toluenediamine (TDA), phenol-formaldehyde-dialkanolamine Mannich condensation products, melamine .

  The functionality of these polyether alcohols is preferably 3 to 8, and the hydroxyl number is preferably 100 mg-KOH / g to 1200 mg-KOH / g, in particular 120 mg-KOH / g to 570 mg-KOH / g. .

  By using a bifunctional polyol as the polyol component, for example, using polyethylene glycol and / or polypropylene glycol having a molecular weight of 500 to 1500, the viscosity of the polyol component can be adjusted.

  These compounds having at least two isocyanate-reactive hydrogen atoms also contain a chain extender and a crosslinking agent which are used as necessary. Rigid polyurethane foams can be produced with or without the use of chain extenders and / or crosslinkers. It is believed that the addition of a bifunctional chain extender, a trifunctional or higher functional crosslinker, or a mixture thereof if necessary is effective in adjusting the mechanical properties. The chain extender and / or cross-linking agent used is preferably an alkanolamine, in particular a diol and / or triol having a molecular weight of less than 400, preferably in the range of 60-300.

  The chain extender, the crosslinking agent or a mixture thereof is preferably used in an amount of 1 to 20% by mass, preferably 2 to 5% by mass, based on the polyol component. Usually these polyurethane foams are produced in the presence of a blowing agent. The blowing agent used is preferably water, which reacts with isocyanate groups to release carbon dioxide. Another frequently used chemical blowing agent is formic acid, which reacts with isocyanates to release carbon monoxide and carbon dioxide. A so-called physical foaming agent may be used together with or instead of the chemical foaming agent. Physical foaming agents typically include compounds that are inert to the feed components and liquid at room temperature that vaporizes under urethane reaction conditions. The boiling point of these compounds is preferably less than 50 ° C. Physical blowing agents also include compounds that are gaseous at room temperature and charged and / or dissolved in the feed components under pressure. Examples thereof are carbon dioxide, alkanes (specifically, low boiling point alkanes) and fluoroalkanes, preferably alkanes (specifically, low boiling point alkanes) and fluoroalkanes.

Physical blowing agents are usually alkanes and / or cycloalkanes with at least 4 carbon atoms, dialkyl ethers, esters, ketones, acetals, fluoroalkanes with 1 to 8 carbon atoms, 1 to 1 in the alkyl chain. Examples selected from the group consisting of tetraalkylsilanes having 3 carbon atoms (specifically, tetramethylsilane) include propane, n-butane, isobutane, cyclobutane, n-pentane, isopentane, cyclopentane, and cyclohexane. , Dimethyl ether, methyl ethyl ether, methyl butyl ether, methyl formate, acetone, and fluoroalkanes that are decomposed in the troposphere and are therefore harmless to the ozone layer (for example, trifluoromethane, difluoromethane, 1,1,1, 3,3-pentafluorobutane 1,1,1,3,3-pentafluoropropane, 1,1,1,2,3-pentafluoropropene, 1-chloro-3,3,3-trifluoropropene, 1,1,1,2 -Tetrafluoroethane, difluoroethane, 1,1,1,2,3,3,3-heptafluoropropane) and perfluoroalkanes (for example, C3F8, C4F10, C5F12, C6F14, C7F16). Hydrocarbons are preferred, preferably pentane, especially cyclopentane. The above physical foaming agents may be used alone or in any desired combination with each other.

  In one preferred embodiment of the invention, a mixture of physical and chemical blowing agents can be used. A mixture of physical blowing agent and water, specifically a mixture of hydrocarbon and water, is particularly preferred. Particularly preferred among the hydrocarbons is pentane, and among these, cyclopentane is particularly preferred.

  The production of the polyurethane may be carried out in the presence of catalysts, flame retardants and commonly used auxiliaries and / or additives, if necessary.

  Details of the starting compounds used are described, for example, in Kunststoffhandbuch, volume 7 “Polyurethane”, edited by Gunter Oeltel, Carl-Hanser-Verlag Munch, 3rd edition, 1993.

  Rigid PU foam is used as a heat insulating intermediate layer in composite materials, to fill refrigeration equipment housings, specifically in hollow spaces in refrigerators and box-type freezers containing foam, and to coat hot water storage tanks It is preferable to use it as a material. These products are useful for thermal insulation of heated materials, for example as engine covers and pipe shells. A composite or sandwich structure comprising a hard PU foam and at least one outer layer made of a hard or soft material such as paper, polymer film, aluminum foil, metal sheet, glass veil or particle board provided thereon Use in the manufacture of goods is also known. It is also known to fill a hard space as a heat insulating material into a hollow space in a household device such as a refrigerator or a refrigerator such as a box-type freezer or a hot water storage system. Another application is an insulating pipe consisting of an inner pipe made of metal or plastic, an insulating polyurethane layer and an outer jacket made of polyethylene. Insulation of a large storage container or a transport ship is also possible. For example, a liquid or liquefied gas having a temperature range of 160 ° C to -160 ° C can be stored and transported. As is well known, heat insulating and cold insulating hard PU foams suitable for these purposes are organic polyisocyanates and one or more compounds having at least two isocyanate-reactive groups, preferably polyester polyols and It can be produced by a reaction with a polyether polyol, usually in combination with a chain extender and / or a crosslinking agent in the presence of a blowing agent and a catalyst, and if necessary, auxiliary and / or additive substances. By appropriately selecting the reactive component, it is possible to obtain a rigid PU foam having low mechanical conductivity and excellent mechanical properties.

  A review of the production of rigid PU foam and its use as an outer or preferably intermediate layer of the composite material, its use as a thermal insulation layer in the refrigeration or heating arts, for example, Polyurethane, Kunststoff-Handbuch, volume 7, 3rd. edition 1993, edited by Dr. Seen in Gunter Oeltel, Carl Hanser Verlag, Munich, Vienna.

  The following examples illustrate the invention.

Polyol adjustment:
Example 1:
Preparation of polyols 2, 3 and 5 of the present invention

Polyol 2
A 960 l pressure reactor equipped with a stirrer and a jacket heating and cooling type solid and liquid substance containing alkylene oxide, a nitrogen deactivator, and a vacuum system is heated to 80 ° C. and dried, and repeatedly with nitrogen. Activated. 18.38 kg of glycerol and 1.26 kg of DMEOA were charged and the stirrer was started. Sucrose (191.6 kg) was then added to the reactor and the temperature was raised to 95 ° C. At 95 ° C., the mixture was reacted with 54.0 kg of propylene oxide. After a 30 minute post reaction, an additional 0.64 kg of DMEOA was added. The temperature was then raised to 112 ° C. and 116 kg of propylene oxide was added. The post reaction was carried out at 112 ° C. for 3 hours. The product was stripped at 105 ° C. (vacuum, nitrogen) for 2 hours to give 352 kg of product with the following values:
Hydroxyl number: 444 mg-KOH / g
Viscosity: 15300 mPas
Moisture content: 0.013%
pH: 9.7

Polyol 3
A 600-liter pressure reactor equipped with a stirrer and jacket heating and cooling type solid and liquid substance containing alkylene oxide, nitrogen deactivator, and vacuum system is heated to 80 ° C. and dried, and repeatedly with nitrogen. Activated. 58.2 kg of glycerol and 6.0 kg of dimethylethanolamine were added and the stirrer was started. Sucrose (191.6 kg) was then added to the reactor and the temperature was raised to 95 ° C. At 105 ° C., this mixture was reacted with 195.0 kg of propylene oxide. The temperature was then raised to 112 ° C. and the product was further reacted with 352.7 kg of propylene oxide. The post reaction was carried out at 112 ° C. for 3 hours. The remaining propylene oxide was removed by stripping in a nitrogen stream to obtain 770 kg of product having the following values:
Hydroxyl number: 455 mg-KOH / g
Viscosity: 14800 mPas
Moisture content: 0.03%
pH: 9.8

Polyol 5
A 600 liter pressure reactor equipped with a stirrer and jacket heating and cooling type solid and liquid substance containing alkylene oxide, nitrogen deactivator, and vacuum system is heated to 75 ° C. and dried, and repeatedly with nitrogen. Activated. 17.00 kg of glycerol and 3.09 kg of dimethylethanolamine were added and the stirrer was started. Sucrose (154.75 kg) was then added to the reactor and 157.50 kg of PO was charged at 75-95 ° C.

After a reaction at 105 ° C. for 30 minutes, 1.55 kg of DMEOA was further added, and 254.50 kg of PO was added. The post reaction was carried out at 105 ° C. for 2 hours. The remaining propylene oxide was removed by stripping in a nitrogen stream to give 770 kg of product.
Hydroxyl number: 468 mg-KOH / g
Viscosity: 21300 mPas
Moisture content: 0.016%
pH: 10.2

Example 2:
Comparative polyols 1 and 4 for adjustment polyol 1:
A 50 liter pressure reactor equipped with a stirrer and jacket heating and cooling type solid and liquid substance containing alkylene oxide, a nitrogen deactivator, and a vacuum system is heated to 90 ° C. and dried, and repeatedly with nitrogen. Activated. 2.87 kg of glycerol, 0.188 kg of 48% KOH solution and 0.065 kg of water were added and the agitator was started. Sucrose (9.48 kg) was then added. The temperature was raised to 105 ° C. and 7.53 kg was added. After 1 hour reaction time, the temperature was raised to 112 ° C. and the remaining PO (19.85 kg) was charged. The resulting polyetherol was hydrolyzed with water, neutralized with phosphoric acid, filtered and stripped in vacuo to give 39.1 kg of product.
Hydroxyl number: 450 mg-KOH / g
Viscosity: 19500 mPas
Moisture content: 0.07%
pH: 9.2

Polyol 4
A 50 liter pressure reactor equipped with a stirrer and jacket heating and cooling type solid and liquid substance containing alkylene oxide, a nitrogen deactivator, and a vacuum system is heated to 90 ° C. and dried, and repeatedly with nitrogen. Activated. 4.00 kg glycerol, 0.245 kg 48% KOH solution and 0.049 kg water were added and the agitator was started. Sucrose (13.16 kg) was then added and 11.7 kg of PO was added at 105 ° C. After 3 hours post-reaction, the temperature was raised to 112 ° C. and the remaining PO (22.3 kg) was charged. The resulting polyetherol was hydrolyzed with water, neutralized with phosphoric acid, filtered and stripped to give 41.5 kg of product.
Hydroxyl number: 477 mg-KOH / g
Viscosity: 22300 mPas
Acid value: 0.012 mg-KOH / g
Moisture content: 0.023%
pH: 10.2

Method:
Viscosity measurement:
Unless otherwise stated, the viscosity of polyols and polyol mixtures was measured using a Rheotech RC20 rotational viscometer with spindle CC25DIN (spindle diameter: 12.5 mm; graduated cylinder inner diameter: 13.56 mm) at 25 ° C. with a shear rate of 50 s ^{− 1} was measured.

Hydroxyl number
The hydroxyl number was measured according to DIN 53240.

Thermal conductivity:
The thermal conductivity was measured according to DIN 52616. To make the test specimens, the polyurethane reaction mixture was poured into a mold with dimensions of 200 × 20 × 5 cm (10% overfill) and after a few hours, test specimens with dimensions of 20 × 20 × 2 cm were cut from the center.

Compressive strength:
The compressive strength was measured by DIN5341 / DIN-EN-ISO604.

Measurement of pentane solubility:
50 g of polyol or polyol mixture is placed in a 100 mL glass container. Add a certain amount of cyclopentane. The glass container is then sealed, shaken vigorously for 5 minutes and left for 1 hour. Thereafter, the appearance of the sample is inspected. If the sample is clear, repeat this test with more cyclopentane. If the mixture is clogged, repeat this test with less cyclopentane. In this way, the maximum amount of cyclopentane soluble in the polyol or polyol mixture is determined. This amount is the pentane solubility of the polyol or polyol mixture. The accuracy of this method is 1%.

Production of foam for mechanical testing:
Foam molding experiments were conducted using the following basic composition:
100 parts by weight of polyol (or polyol mixture)
2.4 parts by weight of stabilizer (Tegostab (registered trademark) B8467 manufactured by Evonik)
0.85 parts of water Dimethylcyclohexylamine Cyclopentane Polymeric MDI (Lupranate M20 (registered trademark) manufactured by BASF)
These foams are produced with an isocyanate index of 100. In a beaker test in which the initial total mass was 50 g, the stirring time was 10 seconds, and the set time was 55 seconds, the amounts of dimethylcyclohexylamine and cyclopentane were determined so as to obtain a free foam material density of 35 g / L. In the second test, these components were mixed vigorously using a lab stirrer and charged into a cubic foam mold steel mold (500 g reaction mixture, mold volume: 11.4 L). After 20 minutes, the reacted foam sample was removed from the mold and stored under standard conditions for an additional 3 days. The density was measured by ISO845 and the compressive strength was measured by ISO604.

  Table 1 outlines the polyols used.

  Table 2 compares the properties of the sucrose-polyol system.

  Tables 3 and 4 outline the systems obtained with the polyol mixture.

Notes on Tables 2-4:
The amine-catalyzed polyol more effectively utilizes cyclopentane used as a blowing agent. A smaller amount of cyclopentane can be used to produce a foam with the same material density. Due to the autocatalytic properties of amine-catalyzed polyols, the amount of catalyst used can be reduced. Improved pentane solubility and reduced viscosity are obtained not only when using polyols prepared with amine catalysts (Table 2) but also when using mixtures containing such polyols (Tables 3 and 4). It was. The mechanical properties are the same.

Mechanical foam:
A polyol component was produced using the above raw materials. In a high-pressure Pullmat (registered trademark) HD30 (Elastolan Co., Ltd.), the polyol component was mixed with the required amount of the isocyanate to give an isocyanate index of 110. The reaction mixture was placed in a mold having dimensions of 200 cm × 20 cm × 5 cm or 40 cm × 70 cm × 9 cm and foamed therein. The properties and values of the foam are shown in Tables 5 and 6.

  Foam using a box-shaped mold with dimensions of 70 x 40 x 9 cm, measure the height of the box after 24 hours, and post-foaming as a function of the time to remove from the mold and the degree of overfill (OP) Were determined. The surface quality was determined by measuring the frequency and strength of surface cracks with the naked eye (0: reference, +: less cracking and less surface cracking strength than reference).

Summary of results Notes on Tables 5 and 6:
The functionality and OH number are the same, but the viscosity of the DMEOA catalyst polyol is as low as 3000 mPas. This difference is large and also manifests as a decrease in the viscosity and flow coefficient of the polyol component and an improvement in surface quality (reduction in the number of pore spaces). Other important performances for this application of rigid foam are about the same.

Claims (15)

a) Polyisocyanate
b) a compound having at least two isocyanate group-reactive hydrogen atoms;
c) A method for producing a rigid polyurethane foam comprising a step of reacting in the presence of a foaming agent,
Compound b) having at least two isocyanate group reactive hydrogen atoms is
By using amine b1c) as a catalyst, it is obtained by adding alkylene oxide b1b) to compound (b1a) (hereinafter also referred to as starting material) having an alkylene oxide reactive hydrogen atom, and has a functionality of 2 to 2. 8 and at least one polyether alcohol b1) having a hydroxyl number of 200 to 800 mg-KOH / g.   The process according to claim 1, wherein the polyether alcohol b1) is used in an amount of 10 to 90% by weight, based on the weight of the component b).   2. The compound b1a) having at least two alkylene oxide reactive hydrogen atoms used for the production of the polyether alcohol b1) comprises at least one mixture comprising a compound b1ai) which is solid at room temperature. the method of.   Compound b1ai) is pentaerythritol, glucose, sorbitol, mannitol, sucrose, polyphenol, resol, condensate of aniline and formaldehyde, toluenediamine, Mannich condensate of phenol, formaldehyde and dialkanolamine, melamine, and at least 4. A process according to claim 3 selected from the group consisting of a mixture of two of these compounds.   4. The method of claim 3, wherein the compound b1ai) is selected from the group consisting of sucrose, sorbitol and pentaerythritol.   2. The compound b1a) having at least two alkylene oxide reactive hydrogen atoms used for the production of the polyether alcohol b1) comprises at least one mixture comprising a compound b1iii) which is liquid at room temperature. the method of.   The compound b1aii) is a glycerol, a monofunctional alcohol having 1 to 20 carbon atoms, ethylene glycol and its higher homologues and propylene glycol and its higher homologues, hydroxy such as monoethanolamine, diethanolamine and triethanolamine 7. A process according to claim 6 selected from the group consisting of alkylamines and their reaction products with propylene oxide.   The process according to claim 1, wherein the compound b1a) comprises a mixture of at least one compound b1ai) which is solid at room temperature and at least one compound b1ai) which is liquid at room temperature.   The process according to claim 1, wherein an amine other than the amine of b1ai) is used as the catalyst b1c).   The process according to claim 1, wherein the catalyst b1c) is selected from the group consisting of trialkylamines, aromatic amines, pyridine, imidazole, guanidine, alkylated guanidines and amidines.   The process according to claim 1, wherein the catalyst b1c) is dimethyl-ethanolamine.   The process according to claim 1, wherein the catalyst b1c) is imidazole.   The catalyst b1c) is in an amount of 0.01 to 5.0% by weight, preferably 0.05 to 3.0% by weight, more preferably 0, based on the total batch for the production of the component b1). The method according to claim 1, which is used in an amount of from 1 to 1.0% by mass.   The method according to claim 1, wherein a hydrocarbon is used as the blowing agent.   The rigid polyurethane foam obtained by the manufacturing method as described in any one of Claims 1-14.