DE2448216A1 - POLYURETHANE FOAM - Google Patents

Description

The invention relates to polyurethane foams into which a carbohydrate has been incorporated and to the production of such foams.

Polyurethane foam materials are well known and are made by reacting active hydrogen containing Compounds, in particular polyols, with polyisocyanates in the presence of blowing agents and, if appropriate, auxiliaries, such as catalysts and surfactants of various types.

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From GB-PS 1 O 30 l62 and 1 029 903 it is known Polyisocyanates with compounds containing active hydrogen atoms and particulate, previously prepared To implement aminoplast resin condensation products. It is also known from the same PSs to be a saccharide or polysaccharide to incorporate in the aminoplast resin condensation product and then the mixture at the above to use mentioned polyurethane foam reaction, whereby a heat-insulating inflated cellular foam is formed.

It has now been found that the incorporation of a carbohydrate in polyurethane foam-forming mixtures in The absence of an aminoplast resin results in a foam with increased hardness, which can be used, for example, as shock padding can be used. The foam also has improved fire resistance because of the fire spread by particles of burning molten urethane polymer is decreased.

Thus, according to the invention, there are foamed cellular polyurethane materials proposed which have a carbohydrate filler, with aminoplast resins being absent.

The foamed polyurethane material of the present invention may, for example, be hard, semi-hard, semi-flexible or be flexible material.

According to a further embodiment of the invention, a Process for the production of foamed cellular polyurethane materials proposed which is carried out by having polyurethane foaming reactants in Presence of a propellant and a carbohydrate in ab-

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Essence of any aminoplast resin reacts with one another.

Any of the polyurethane foaming reactants known in the art can be used be used. For example, the polyisocyanate, which contains at least two isocyanate groups, be any polyisocyanate described in the literature on the manufacture of polyurethanes.

Preferred polyisocyanates. are tolylene diisocyanates, in particular a mixture of 2,4- and 2,6-isomers, or a diphenylmethane diisocyanate, especially the mixtures of Polypheny! Polyisocyanates containing methylene bridges, which contain diphenylmethane diisocyanate together with polyisocyanates of higher functionality and which are produced by phosgenation of the crude mixture of di- and higher polyamines, this mixture being produced by condensation of aniline and formaldehyde in the presence of catalysts, especially acidic catalysts, for example hydrochloric acid, can be obtained.

Examples of active hydrogen containing compounds that can be reacted with the polyisocyanate are any such connections, in particular connections, which contain two or more hydroxyl groups, especially hydroxyl-terminated polyesters, polyesteramides and polyether.

Suitable polyesters or polyester amides can, for example, from dicarboxylic acids and polyhydric alcohols and if necessary smaller amounts of diamines or amino alcohols can be produced. Suitable dicarboxylic acids are amber,

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Glutaric, adipic, corkic, azelaic and sebacic acids, as well as aromatic acids such as phthalic, isophthalic and terephthalic acid. Mixtures of acids can also be used. Examples of polyhydric alcohols are glycols, such as ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, diethylene glycol, Tetramethylene glycol and 2,2-dimethyltrimethylene glycol. Other polyhydric alcohols that contain more than 2 hydroxyl groups per molecule can also be used, such as trimethylolpropane and other hexanetriols, trimethylolethane, Pentaerythritol and glycerin. Such compounds are used in various ways in the polyester production reaction Amounts incorporated depending on the desired stiffness of the finished polyurethane product.

In addition to the polyhydric alcohols and dicarboxylic acids, compounds can also be reacted with which more contain as two hydroxyl, carboxylic and secondary acid and primary amino groups. Examples are diethanolamine, Trimesic acid, dihydroxystearic acid and tricarballylic acid.

Examples of diamines and amino alcohols used to manufacture

can be used by polyester amides are ethylene

diamine, hexamethylenediamine, monoethanolamine, phenylenediamines and tolylenediamines.

The polyesters and polyester amides normally have molecular weights from 200 to 5000, with predominantly primary hydroxyl end groups being present.

Example of polyether for use in manufacture of the polyurethane materials are hydroxyl capped polymers

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and mixed polymers of cyclic oxides, such as 1,2-alkylene oxides, for example ethylene oxide, epichlorohydrin, 1,2-butylene oxide, Oxacyclobutane and substituted oxacyclobutanes, and tetrahydrofuran. Such polyethers can be linear polyether glycols be, for example, by polymerizing an alkylene oxide in the presence of a basic catalyst, such as potassium hydroxide, and a glycol or a primary monoamine. Alternatively, branched Polyethers are used, for example, by polymerizing an alkylene oxide in the presence of a basic Catalyst and a substance with more than two active Hydrogen atoms per molecule can be obtained, e.g. with ammonia, hydrazine and polyhydroxy compounds, for example glycerine, trimethylolpropane and other hexanetriols, Trimethylolethane, triethanolamine, pentaerythritol, sorbitol, Sucrose and phenol / formaldehyde reaction products, amino alcohols such as monoethanolamine and diethanolamine, and Polyamines such as ethylene diamine, tolylene diamine and diaminodipheny! Methane. Branched polyethers can also be obtained by copolymerization of a cyclic oxide of those already mentioned Types with cyclic oxides that have a functionality of more than two, such as diepoxides, glycidol and 3-hydroxymethyloxacyclobutane, getting produced. Polypropylene glycols and related compounds that have ethylene oxide tips, can also be used.

The polyethers normally have molecular weights of 200 to 8,000. Mixtures of linear and branched polyethers can also optionally be used.

Non-polymeric oxyalkylation products of active hydrogen containing compounds can be used in the preparation of the poly

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urethane materials are used. examples for this are Polyhydroxy compounds in which the degree of oxyalkylation is sufficiently high that the compounds have several ether groups exhibit. In particular, non-polymeric Oxyalkylation products of primary and secondary polyamines such as the reaction products of tolylenediamine with up to 5 moles of alkylene oxide.

Mixtures of isocyanate-reactive compounds can also optionally be used.

When foamed cellular polyurethane materials through the Processes according to the invention are prepared, then the polyurethane formation reaction is carried out in the presence of a blowing agent carried out under such conditions that a foaming gas is generated.

The foaming gas can be generated by various methods. For example, the gas can be carbon dioxide be that by reaction of part of the organic polyisocyanate with water incorporated into the reaction mixture is formed. Alternatively, the gas can be generated by adding a suitable low temperature to the reaction mixture boiling liquid incorporated when the reaction mixture is heated above the boiling point of said liquid volatilizes, creating the foam-forming gas. Combinations of methods such as a combination of the above two methods can also be used.

The water is usually present in amounts of 1 to 10 wt -.% With respect _t to the polyhydroxy compound used when it is used as a gas generating agent.

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Suitable low-boiling liquids are liquids that are inert to the polyurethane foam forming ingredients and do not have boiling points at atmospheric pressure of over 75 ° C and preferably between -40 and +50 ⁰ C. Examples of such liquids are halogenated hydrocarbons, such as methylene chloride, trichloromonofluoromethane, dichlorodifluoromethane, dichloromonofluoromethane, monochlorodifluoromethane, dichlorotetrafluoromethane, 1,1,2-trichloro-1, 2y2-trifluoromethane and mono-difluoromethane, difluoromethane and monodifluoromethane, 2y2-trifluoromethane, dibromodifluoromethane. Mixtures of these low-boiling liquids with one another or with other substituted or unsubstituted hydrocarbons can also be used. Such liquids are usually used in amounts of 1 to 100% by weight, preferably 5 to 50% by weight, based on the isocyanate-reactive compound.

The production of foamed polyurethane materials can be by a one-shot process or by a prepolymer process η take place.

Additives used in technology for incorporation in polyurethane foam approaches are known, can also be used in the method according to the invention. Such additives are, for example, surface-active agents such as oxyethylated fatty alkylphenols, oxyethylated fatty alcohols, Salts of sulfuric acid derivatives of high molecular weight organic compounds and alkyl and AryIpοIysiloxane, as well Mixed polymers thereof with alkylene oxides, foam stabilizers, such as ethyl cellulose, coloring agents, plasticizers, fire-proofing agents such as tris-2-chloroethyophosphate and tris-2,3-dibromopropyl phosphate, and antioxidants.

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Often times, catalysts are used in the manufacture of polyurethane materials used. They can also be used in the manufacture of polyurethane materials according to the present invention Procedures are used. Suitable catalysts are tertiary amines, tin (II) salts, for example tin (II) octoate, Organotin compounds such as dibutyltin dilaurate and other metal salts and organic metal compounds known in the art.

It is an essential feature of the present invention that the foaming mixture contains a carbohydrate as a filler is incorporated.

Classes of carbohydrates that can be used here are sugars, starches, celluloses, and other mono-, di- and Polysaccharides.

Preferred carbohydrates are disaccharides and higher polysaccharides.

Examples of special carbohydrates are corn starch, wheat starch, sucrose, lactose, maltose, fructose, dextrin, Potato starch, rice starch, arrowroot starch, sago starch, hydrocellulose, cellulose, wood flour and whey powder.

Mixtures of carbohydrates can also be used

The invention is illustrated in more detail by the following examples, in which all parts and percentages are by weight are expressed unless otherwise specified.

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example 1

To 200 parts of a glycerine / poly (oxypropylene / oxyethylene) polyol with a molecular weight of 5300, the $ 75 primary Containing hydroxyl groups, 29.4 parts were powdered Corn starch added. The mixture was stirred with a high performance stirrer and 82 parts of a 2,4- / 2,6-tolylene diisocyanate mixture (80:20 ratio) was then added, followed by the addition of 12 parts of a Mixtures of the following composition followed:

7 parts of water

2 parts of a condensate of octylphenol with

7 moles of ethylene oxide

1 part siloxane / oxyalkylene mixed polymer 1 part Ν, Ν-dimethyl-ß-phenylethylamine 0.2 parts of tin (II) octoate.

After stirring for an additional 30 seconds to ensure complete mixing, the mixture was poured into a suitable mold and allowed to rise. Well-structured foams were obtained after standing overnight. Density 0/041, compression deformation at 25% compression 4.7 KNM " ² , at 65% compression 14.8 K, NM" ² ,

A comparative experiment using the same recipe but omitting the starch produced a similar but softer foam. Density 0.39 * mandrel]:
-2

Deformation at $ 25 compression 3.8 KNM, at 65% compression 10.1 KNM
Example 2

Example 1 was repeated, except that the amount of starch was increased from 29.4 parts to 73.5 parts. It was

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get a well-structured elastic foam, eggs but was harder than that of Example 1st Density

K " ²

Compression set at 25% compression 5.5 KNM, at $ 65

Compression 14.4 KN, M. ' Example 3

Example 1 was repeated, except that the amount of starch was increased from 29.4 parts to 147 parts. A good foam was obtained, but it was harder than that of Example 2. Density 0.0498, compression set at 25 $ compression 6.3 KNM " ² , at 65% compression 23.2 KNM" ² .

Example 4

Example 1 was repeated, except that the amount of starch was replaced by 29.4 parts of powdered sucrose. A finely structured elastic foam was obtained which was harder than the comparison foam of Example

Example 5

Example 4 was repeated, except that the amount of sucrose was increased from 29.4 parts to 73.5 parts. It became a similar foam was obtained, but it was harder than that of example

Example 6

Example 4 was repeated, except that the amount of sucrose was increased from 29.4 parts to 147 parts. It turned out to be a good one Foam was obtained which was similar to that of Example 4, but had a greater hardness.

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Example 7

Example 1 was repeated, except that the amount of starch through 29, ¹ J parts of wheat flour was replaced. A well-structured elastic foam was obtained which was harder than the comparison foam from Example 1.

In all of Examples 1 through 7, the foams burned in a manner similar to, but possessed, the comparative foam considerable advantage over the comparison foam (no added carbohydrates) that a char was formed which would cause the dripping off of burning molten polyurethane prevented during a fire. The comparison foam burned slightly, with burning molten Polyurethane dripped off.

PATENT CLAIMS:

Mt-KiG. H. FINCKE DIPL-ING. H. iOW » . S. STAtGBS

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Claims (7)

PATENT CLAIMS 1. Foamed cellular polyurethane material, characterized in that that it contains a carbohydrate filler and that aminoplast resins are absent. 2. A method for producing a foamed cellular polyurethane material, characterized in that one Polyurethane forming reactants in the presence and absence of a blowing agent and a carbohydrate an aminoplast resin reacted with one another. 3. The method according to claim 2, characterized in that the polyurethane forming reactants comprise a polyisocyanate and a polyol and that the polyisocyanate is a mixture of the 2, ¹ I and 2,6 Iosmeres of tolylene diisocyanate. k. Process according to claim 2, characterized in that the polyurethane-forming reactants comprise a polyisocyanate and a polyol, and in that the polyisocyanate is a mixture of methylene-bridged polypheny-polyisocyanates which contains diphenylmethane diisocyanate together with polyisocyanates of higher functionality. 5. The method according to any one of claims 2 to 4, characterized characterized in that one of the polyurethane formation reaction participants a polyester or polyester amide. a molecular weight of 200 to 5000. 6. The method according to any one of claims 2 to k _t thereby 509815/1186 characterized in that one of the polyurethane-forming reaction participants is a polyether having a molecular weight of 200 to 8000 is. 7. The method according to any one of claims 2 to 6, characterized in that the carbohydrate is a disaccharide or is a higher polysaccharide. WKtNTANWAtTB MMNG.H.F1NCKE. WPL-ING. a BOW » DiPUINO. 8. STAESK 5098 15/1186