MXPA00000607A - Low fogging catalysts for producing polyurethanes - Google Patents

Abstract

Low-fogging catalysts for polyurethane (PU) production, obtained by reacting (a) polymeric compounds containing carboxylic acid and/or anhydride groups with (b) compounds with primary or secondary amino group(s) and/or compounds with tertiary amino group(s) and group(s) which react with acid or anhydride groups. Independent claims are also included for:(i) A process as described above for the production of low-fogging catalysts;(ii) a process for the production of PU by reacting polyisocyanates with compounds containing at least two isocyanate-reactive groups in presence of these catalysts;(iii) polyurethanes obtained by this process.

Description

LOW CLOUDED CATALYSTS FOR THE PRODUCTION OF POLYURETHANE The invention relates to cloudy low catalysts for the production of polyurethanes, their preparation and their use. Polyurethanes have been known for a long time and are widely described in the literature. They are usually produced by the reaction of polyisocyanates with compounds containing at least two hydrogen atoms which react with the isocyanate groups. The reaction is usually carried out in the presence of catalysts. Preferred catalysts are, apart from heavy metal salts, compounds containing amino groups, particularly secondary and tertiary amino groups. These amino compounds have very good catalytic properties, however, they have the disadvantage of having a strong odor which represents a big problem in the production of polyurethane. Another particularly unpleasant aspect is that the amine catalysts are often not integrated into the polyurethane structure and migrate from the polyurethane over time. This migration of constituents of polyurethane, which is also known as cloudy, is a real quality defect in polyurethanes. To alleviate this deficiency, it has been proposed, for example, that the amines used as catalysts be provided with functional groups in such a way that they can be integrated into the polyurethane structure. US-A 3,448,065 and EP-A-451 826 disclose hydroxyalkylimidazoles which can be integrated into the polymer structure through its hydroxyl group. EP-A-677 540 describes a process for the production of flexible polyurethane foams which use, as catalysts, substituted imidazoles carrying active hydrogen atoms in their substituents and can be integrated into the polymer structure through these. A disadvantage here is that the usual monofunctional substituted imidazoles act as chain terminators during the urethane formation reaction and also do not remain freely movable in the reaction mixture because they are quickly fixed in the polymer structure. This can cause lack of homogeneity in the polyurethane. In addition, these compounds are difficult to synthesize. It is an object of the present invention to provide catalysts for producing polyurethanes that do not migrate from the polyurethane, do not cause problems in the polyurethane formation reaction, and, moreover, are simple in obtaining them. We have found that this object is achieved through low cloudy catalysts for the production of polyurethanes which can be prepared by the reaction of polymeric compounds containing carboxyl groups and / or carboxylic anhydride groups with compounds having at least one primary and secondary amino group and / or with compounds having at least one tertiary amino group and at least one group that reacts with carboxyl groups and carboxylic anhydride groups. The present invention therefore offers low clouded catalysts for the production of polyurethanes which can be prepared by the reaction of polymeric compounds containing carboxyl groups and / or carboxylic anhydride groups with compounds having at least one primary or secondary amino group and / or with compounds having at least one tertiary amino group and at least one group that reacts with carboxyl groups and carboxylic anhydride groups. The invention also offers a process for the preparation of said catalysts. The invention also offers the use of low clouded catalysts of the present invention for the production of polyurethanes. The present invention also provides a process for the production of polyurethanes by reacting polyisocyanates with compounds containing at least two hydrogen atoms which react with isocyanates, wherein compounds which can be prepared by the reaction of polymeric compounds containing carboxyl groups and / or carboxylic anhydride groups with compounds having at least one primary or secondary amino group and / or with compounds having at least one tertiary amino group and at least one group that reacts with carboxyl groups and carboxylic anhydride groups are used as catalysts. The low cloudy catalysts of the present invention can, as established, be prepared by the reaction of polymeric compounds containing carboxyl groups and / or carboxylic anhydride groups with compounds having at least one primary or secondary amino group and / or with compounds having at least one tertiary amino group and at least a group that reacts with carboxyl groups and carboxylic anhydride groups. As polymeric compounds containing carboxyl groups and / or carboxylic anhydride groups, it is preferred to use compounds prepared by the polymerization of ethylenically unsaturated carboxylic acids and / or carboxylic anhydrides or by the copolymerization of ethylenically unsaturated carboxylic acids and / or carboxylic anhydrides with other monomers ethylenically unsaturated. As ethylenically unsaturated carboxylic acids and / or carboxylic anhydrides, it is preferred to use maleic acid, maleic anhydride, (meth) acrylic acid, itaconic acid, citraconic acid, mesaconic acid, fumaric acid, methylmalonic anhydride, especially maleic acid, maleic anhydride or well acid (meth) acrylic. Suitable ethylenically unsaturated monomers are, in particular, styrene and all C2-C0 olefins with which those skilled in the art are familiar and are known from the literature. Preference is given to using monoolefins having at least 4, preferably at least 6 and in particular at least 8 carbon atoms. Particularly preferred compounds are diisobutene, C_2 olefins / Cis olefins and C2o-2 olefins. As polymeric compounds containing carboxyl groups and / or carboxylic anhydride groups, polymaleic anhydride, copolymers of maleic anhydride and diisobutene, copolymers of anhydride are preferably employed maleic and polyisobutylene, copolymers of maleic anhydride and C12 olefins copolymers of maleic anhydride and C? 8 olefins and / or copolymers of maleic anhydride and C2o? C24 olefins. The molecular weight of these polymeric compounds is preferably within a range of 350 to 15,000. These polymers are prepared using known methods by polymerization of the unsaturated monomers. Such products are in commerce. They are produced, for example, BASF Aktiengesellschaft under the name Sokalan®. As compounds having at least one primary or secondary amino group and / or compounds having at least one tertiary amino group and at least one group reacted with carboxyl groups and carboxylic anhydride groups, compounds having the following structures are preferably used - CH3 Hj-S Rl H <i) CE3 H2H - - R N j (") ^ CH3 SO R N (III) CH3 ao- -R N (IV) * CH3 where R can be identical or different and each is a linear or branched aliphatic radical having from 1 to 20, preferably from 2 to 10 carbon atoms. Low cloudy catalysts of the present invention for the production of polyurethanes are prepared by reacting polymeric compounds containing carboxyl groups and / or carboxylic anhydride groups, mentioned below as polymeric compounds, with compounds having at least one primary amino group or secondary and / or with compounds having at least one tertiary amino group and at least one group that reacts with carboxyl groups and carboxylic anhydride groups, This reaction is preferably carried out stoichiometrically. It is also possible to use a deficiency of amines. Here, the acid and / or anhydride groups react with the groups that react with them in a first step and the acid or anhydride groups that did not react are neutralized by reaction with bases in a second step. As bases, preference is given to the use of oxides and / or hydroxides of base metals, preferably oxides and / or hydroxides of alkali metals and / or alkaline earth metals and / or tin oxides and / or bismuth oxides, with hydroxides being particularly preferred. of alkali metals. In principle it is also possible to use an excess of amine. However, this can result in free amine remaining in the catalyst, such that it will occur cloudy. The reaction of the polymeric compounds with the compounds having at least one primary or secondary amino group and / or the compounds having at least one tertiary amino group and at least one group reactive with carboxyl groups and carboxylic anhydride groups can be carried out in volume. However, since the polymeric compounds are usually solid or highly viscous, the reaction is preferably carried out in solution. Suitable solvents are all compounds in which the initial materials are soluble and which are largely inert towards the initial materials and the final products. Preference is given to the use of hydroxyl-containing compounds since these are compatible with the formative components for the polyurethane and the catalyst therefore does not have to be separated from the solvent. Suitable hydroxyl-containing compounds are diols, such as, for example, ethylene glycol and / or propylene glycol, or polyether polyols. In the latter case, preference is given to the use of polyether polyols which are also used for the production of the corresponding polyurethanes. The reaction of the polymeric compounds with the compounds having at least one primary or secondary amino group and / or the compounds having at least one tertiary amino group and at least one group reacted with carboxyl groups and carboxylic anhydride groups is carried out at a temperature comprised within a range of 20 to 170 ° C under atmospheric pressure. When primary amines are used, the reaction is preferably carried out at a temperature in the range of 20 to 90 ° C in order to avoid the formation of imides. When secondary amines are used, the reaction is preferably carried out at a temperature within a range of 90 to 130 ° C. The reaction with the metal oxides and / or hydroxides is preferably carried out at a temperature in the range of 75 to 150 ° C, particularly 100 to 145 ° C. The separation of the low cloudy catalysts of the present invention from the solvent usually, as indicated above, is not necessary. It is also not necessary to carry out any specific treatment of the catalysts of the present invention since the reaction is usually carried out very gently and does not form by-products that can cause problems in the use of the os catalysts for the production of polyurethanes. The reaction must be carried out in such a way that the acid number according to DIN 53 402 of the low clouding catalysts of the present invention is less than 25 mg KOH / g since the catalysis of the polyurethane system can be Accepted negatively with higher acidity indexes. The low clouding catalysts of the present invention are usually employed in solution. The advantages of a procedure of this type are, first, in accordance with the above, that the treatment of the catalysts can be avoided after their preparation. Second, the handling of the catalysts is much easier since as solutions they can be mixed substantially easier with other starting materials of the polyurethane systems. The catalysts of the present invention are used, in particular, as catalysts for the production of polyurethane. In principle, they can be used for all types of polyurethanes, both for compact polyurethanes and for foam polyurethanes. The catalysts of the present invention are preferably used in applications in which clouding represents a particular problem, that is, preferably in the case of polyurethanes to be used in interior parts, particularly polyurethanes intended for use in vehicles to motorcycle They are used particularly advantageously for the production of integral foams which are used in large quantities of interior parts of vehicles, for example, steering wheels, head restraints and other molded parts. The polyurethanes are produced, in accordance with what has already been indicated, by the reaction of polyisocyanates with compounds containing at least two hydrogen atoms which react with the isocyanate groups. Polyisocyanates that can be used herein are all isocyanates having two isocyanate groups in the molecule. It is possible to employ both aliphatic isocyanates and for example hexamethylene diisocyanate (HDI) or isophorone diisocyanate (IPDI) and aromatic isocyanates, preferably such as toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI) or mixtures of diphenylmethane diisocyanate. and polyphenylenepolymethylene polyisocyanates (crude MDI). It is also possible to use isocyanates which have been modified by the incorporation of urethane, uretdione, isocyanurate, allophanate, urethane, and other groups, known as modified isocyanates. As compounds having at least two groups that react with isocyanate groups, it is possible to use amines, mercaptans but preferably polyols. Among polyols, polyether polyols and polyester polyols have the greatest industrial importance. The polyester polyols used for the production of polyurethanes are usually prepared by base-catalyzed addition of alkylene oxides, particularly ethylene oxide and / or propylene oxide, in initiating substances with H functionality. Polyester polyols are usually prepared by esterification of polyfunctional carboxylic acids with polyfunctional alcohols. Compounds having at least two groups that react with isocyanate groups also include chain extenders and / or crosslinkers which may, if desired, be used concomitantly. Such chain extenders and / or crosslinkers are at least bifunctional amines and / or alcohols having molecular weights within a range of 60 to 400. It can also be used, if appropriate, blowing agents, cocatalysts and additives and / or auxiliary It is customary in the industry to mix all the starting materials with the exception of the polyisocyanates to form a polyol component and to react this with the polyisocyanates to produce the polyurethane. A review of the initial materials for the production of polyurethanes and also of the processes used for this purpose can be found, for example, in Kunststoffhandbuch, Volume 7, "Poiyurethane" (polyurethanes), Carl-Hanser-Verlag Munich, Vienna, first edition 1966, second edition 1983 and third edition 1993. The low clouding catalysts of the present invention are usually employed in an amount of 0.005 to 1.0% in-weight, based on the polyol component. To optimize the catalytic action the catalysts of the present invention can be used together with catalysts. Suitable cocatalysts are all common catalysts in the chemistry of polyurethanes. The choice is made based on the specific requirements that polyurethane systems must meet. Apart from its low cloud formation properties, the low clouding catalysts of the present invention have additional advantages. Thus, catalysts having a broad catalytic action can be synthesized by the addition of various compounds in the polymer. This can eliminate the need to add small amounts of several catalysts to the polyurethane system, as is often necessary in another way. Since the catalysts of the present invention are neither toxic nor irritant, they can be handled with a significantly smaller number of problems than the amine catalysts. In addition, they can improve the action of internal mold release agents in the production of molded articles. The invention is illustrated by the following examples: Preparation of low clouding catalysts Example 1 127 g (one mole based on an anhydride group) of a polymer of maleic anhydride and ethylbenzene were dissolved in 370 g of ethylene glycol. At a temperature of 80 ° C, 187 g (1 mol) of bis (dimethylaminopropyl) amine were added dropwise to this solution over a period of 30 minutes. After two hours, the acid number of the reaction mixture was determined in accordance with DIN 53 402, the reaction mixture was heated to a temperature of 90 ° C and, at this temperature, 56 g of sodium hydroxide were added. potassium. The reaction mixture was then heated to a temperature of 80 ° C for 2 hours and subsequently cooled to room temperature. Example 2 The procedure of Example 1 was repeated using one mole of 2-methylimidazole in place of bis (dimethylaminopropyl) amine.

Example 3 The procedure of Example 1 was repeated using 1 mole of aminopropylimidazole in place of bis (dimethylaminopropyl) amine. Example 4 The procedure of Example 1 was repeated using 1 mol of ethylimidazole in place of bis (dimethylaminopropyl) amine.

Example 5 The procedure of Example 1 was repeated using 1 mole of ethylenemethylimidazole in place of bis (dimethylaminopropyl) amine Example 6 The procedure of Example 1 was repeated using 1 mole of methylpiperazine in place of bis (dimethylaminopropyl) amine. Example 7 The procedure of Example 1 was repeated using 1 mole of dimethylaminoethanol in place of bis (dimethylaminopropyl) amine. Example 8 280 g (1 mole based on an anhydride group of a copolymer of maleic anhydride and C? 2 olefin with a molecular weight M w of 6000 g / mol were added at a temperature of 100 ° C. this copolymer during a period of minutes 102 g (1 mol of dimethylaminopropylamine) and the reaction mixture was heated to 140 ° C. After 3 hours, the reaction mixture was cooled to 100 ° C and dissolved at this temperature in ethylene glycol. Example 9 255 g (1 mole based on an anhydride group) of a copolymer of maleic anhydride and diisobutene were heated to a temperature of 100 ° C. 133 g of dimethylaminoethoxyethanol was added dropwise to this copolymer over a period of 30 minutes and the reaction mixture was heated to a temperature of 145 ° C. After 3 hours, the reaction mixture was cooled to 100 ° C and dissolved at this temperature in ethylene glycol and the free carboxyl groups reacted with 56 g of potassium hydroxide (1 mol). Example 10 1206 g (1 mole in base at the saponification index SN of 93) were heated to a temperature of 83 ° C and 187 g (1 mole) of bis (dimethylaminopropyl) amine were added dropwise over a period of 30 minutes. minutes The product resulting from the reaction reacted with 56 g (1 mol) of potassium hydroxide. Production of semi-rigid integral foams. Example 11 (comparison) A polyol component was prepared from the following starting materials: 32.00 parts by weight of a polyetherol initiated using glycerol and water and having a hydroxyl number of 30 mg KOH / g (Lupranol ® 2046 from BASF Aktiengesellschft) 41.85 parts by weight of a polyetherol initiated using dimethylaminodipropylenetriamine (DDT) and having a hydroxyl number of 30 mg KOH / g (Lupranol® VP 9207 from BASF Aktiengesellschaft). 4.00 parts by weight of ethoxylated glycerol having a hydroxyl number of 535 mg KOH / g (Lupranol ® VP 9209 from BASF Aktiengesellschaft) 3.30 parts by weight of a styrene / acrylonitrile-grafted polyether having a hydroxyl number of 25 mg KOH / g and a functionality of 2.6 (Lupranol ® 4100 from BASF Aktiengesellschaft). 2.20 parts by weight of water 4.4 parts by weight of malic acid 1.60 parts by weight of ricinoleic acid 2.00 parts by weight of a propoxylated tripropylenetetramine having a hydroxyl number of 335 mg KOH / g (Lupranol ® VP 9233 from BASF Aktiengesellschaft) 10.00 parts by weight of a polyetherol initiated by trimethylol propane having a hydroxide number of 27 mg KOH / g (Lupranol ® 2042 from BASF Aktiengesellschaft) 0.75 part by weight of a polyetherol initiated with glycerol having a hydroxyl number of 42 mg KOH / g (Lupranol ® 2047 from BASF Aktiengesellschaft) 2.00 parts by weight of ethoxylated sorbitan monooleate as a linking agent 0.30 part by weight of potassium acetate, 25% by ethylene glycol as catalyst 100 part by weight of this polyol component reacted with 47.98 parts by weight of a mixture of diphenylmethane diisocyanate and polyphenylenepolymethylene polyisocyanate (Lupranate DM 20f from BASF Aktiengesellschaft) at an index of 100. The molded parts were produced in a mold of 205mm x 205mm x 4 mm preheated to a temperature of 50 ° C. Due to the compaction, the density was 100 g / 1. In parallel with this, foams with free foam formation were produced in rates. The time of cream formation, fiber time, rise time and density were determined in the foams produced in rates and the cloudy production value in the test plates was determined. Example 12 (In accordance with the present invention) The procedure of Example 11 was repeated using 6 parts by weight of the catalyst of Example 1 in place of potassium acetate. The following parameters were determined for the polyurethanes: Table 1 Example time of cream fiber time lifting time 11 17 68 104 12 16 56 82 Example of cloud formation density 11 66.0 0.12 12 50.2 0.00 the cloud formation value was determined in accordance with DIN 75 201, method B. Production of flexible integral foams Examples 13 to 19 A polyol component was prepared from the following materials initial: 80.50 parts by weight of a polyetherol initiated by glycerol having a hydroxyl number of 28 mg KOH / g (Lupranol ® 2040 from BASF Aktiengesellschaft) 5.00 parts by weight of a polyetherol inserted with styrene / acrylonitrile having a hydroxyl number of 25 mg KOH / g and a functionality of 2.6 (Lupranol® 4100 from BASF of Aktiengesellschaft) 4.50 parts by weight of ethylene glycol 3.00 parts by weight of malic acid, 50% by ethylene glycol 1. 7 parts by weight of the catalysts illustrated in Table 2 100 parts in passage of this polyol component reacted with 47.15 parts by weight of a mixture of 60% by weight of 4,4'-MDI modified with uretdione groups and 40% by weight. weight of crude MDI at an index of 105. The polyol component and the isocyanate component were mixed and formed into foam in a 205 mx 205 mm 4 mm mold preheated to 50 ° C to produce the test plates. The density of the test plates was 500 g / 1 as a result of the compaction. In parallel with this, foaming foam-free cups were produced. The cream time, fiber time, rise time, and density for the foams produced in rates were determined and the value of clouding on the test plates was determined. The catalysts used, the properties of foams for foaming are shown in Table 2. Table 2 Example Catalyst Time of cream Time of fiber 13 (C) 1-methyl-imidazole 13 44 14 example 2 12 31 15 example 3 14 37 16 example 4 14 33 17 example 5 14 33 18 example 6 14 30 19 example 7 15 32 Example time of elevation density formation of cloudy 13 (C) 57 183 32.61 14 35 179 5.23 15 42 187 0.37 16 36 182 8.82 17 36 180 0.45 18 36 179 0.96 19 37 188 4.05 The formation value of nnububbled was determined in accordance with DIN 75 201, method B

Claims (1)

1. REI INDICATIONS A low foaming catalyst for producing polyurethanes, which can be prepared by the reaction of polymeric compounds containing carboxyl groups and / or carboxylic anhydride groups with monocarboxylic and dicarboxylic acid compounds having at least one primary or secondary amino group and / or with compounds having at least one tertiary amino group and at least one group that reacts with carboxyl groups and carboxylic anhydride groups. A low clouding catalyst according to claim 1, wherein the polymeric compounds containing the carboxyl groups and / or carboxylic anhydride groups are homopolymers and copolymers of olefinically unsaturated monocarboxylic and dicarboxylic acids and / or copolymers of olefinic monocarboxylic and dicarboxylic acids unsaturated and C2-Co olefins. A low clouding catalyst according to claim 1, wherein the polymeric compounds containing carboxyl groups and / or carboxylic anhydride groups are polymaleic anhydride, copolymers of maleic anhydride and diisobutene, copolymers of maleic anhydride and polyisobutylene, copolymers of maleic anhydride and C? 2 olefins, copolymers of maleic anhydride and Cis olefins and / or copolymers of maleic anhydride and C2o-2 olefins. The low clouding catalyst according to claim 1, wherein the groups that react with carboxyl groups and carboxylic anhydride groups are primary or secondary amino groups or hydroxyl groups. A low clouding catalyst according to claim 1, wherein the compounds having at least one primary or secondary amino group are id idazoles. A low clouding catalyst according to claim 1, wherein the primary and / or secondary amines used are aliphatic amines. A low clouding catalyst according to claim 1, wherein the primary and / or secondary amines used are polyetheramines. A process for the preparation of low clouding catalysts, comprising the reaction of polymeric compounds containing carboxyl groups and / or carboxylic anhydride groups with compounds having at least one primary or secondary amino group and / or with compounds having minus one tertiary amino group and at least one group that reacts with carboxyl groups and carboxylic anhydride groups. A process according to claim 8, wherein the reaction is carried out in a solvent. The use of a low clouding catalyst according to any of claims 1 to 7 for the production of polyurethane. A process for the production of polyurethanes by reacting polyisocyanates with compounds having at least two groups that react with isocyanate groups in the presence of a catalyst, wherein the catalyst used is at least one low clouding catalyst in accordance with that claimed in any of claims 1 to 7. A polyurethane that can be produced in accordance with that claimed in claim 11.