DE1207619B - Process for the production of polyurethane foams - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

Number:
File number:
Registration date:
Display day:

C08g

German class: 39 b-22/04

1 207 619
J23316IVc / 39b
March 8, 1963
December 23, 1965

The invention relates to an improved method for making polyurethane foams from Reaction products of polyisocyanates containing polyhydroxyl compounds and NCO groups with trihydric alcohols in the presence of a reactive or inert blowing agent.

It is known that polyurethanes can be produced by reacting hydroxyl-containing polymers with organic polymers Produce polyisocyanates and the reaction by adding water and / or an inert, low-boiling point Modify liquid. Among other things, diisocyanates were used as organic polyisocyanates and triisocyanates are used. Because of the difficulties in producing organic triisocyanates it has been proposed to use polyisocyanates obtained by reacting a diisocyanate with a polyhydric alcohol with more than two hydroxyl groups in the molecule in such proportions have been prepared that isocyanate groups in excess over hydroxyl groups ao are present. The use of these diisocyanate-polyhydroxy reaction products however, was due to the gelation or crystallization that occurred during manufacture or the storage of these products can occur and the formation of inhomogeneous or complete of solid products without practical usability is not completely successful.

It has also become known, for the production of polyurethane foams, reaction products of trimethylolpropane with toluene diiso- to use cyanate. However, it has been found that when using only one alcohol after A crystallization of the product takes place in a short time and that usable products are only obtained if a combination of alcohol is used.

It has now been found that these difficulties can be avoided or reduced to a minimum by using polyisocyanates which are the reaction product of tolylene diisocyanates and polyhydric alcohols in certain proportions. These polyisocyanates practically do not gel or crystallize, and they are easily compatible with both linear and branched hydroxyl-containing polymers. Furthermore, the foams derived from these products have excellent mechanical properties, e.g. B. have high resistance to compression and high tensile strength, and they can be produced with exceptionally uniform pore structure and low density.
The method according to the invention is thereby ge-method for the production of
Polyurethane foams

Applicant:

Imperial Chemical Industries Limited, London

Representative:

Dr.-Ing. H. Fincke, Dipl.-Ing. H. Bohr

and Dipl.-Ing. S. Staeger, patent attorneys,

Munich 5, Müllerstr. 31

Named as inventor:

John Frederick Chapman,

John Alwyn Hall,

Dennis John Cecil Wood,

Manchester, Lancashire (UK)

Claimed priority:

Great Britain March 8, 1962 (9033)

indicates that one having as NCO-groups, reaction products of polyisocyanates with trihydric alcohols, the product used, the ₀ obtained by reacting 10 to 40 ° / of the isocyanate groups of toluene diisocyanate with a mixture of two or more, at least three OH-group-containing aliphatic alcohols has been.

The tolylene diisocyanates reacted with the compounds with at least three hydroxyl groups in the molecule are preferably the 2,4- or 2,6-isomers or mixtures thereof.

Suitable compounds with at least three hydroxyl groups in the molecule are aliphatic trivalent Alcohols e.g. B. glycerine, trimethylolethane, trimethylolpropane or other hexanetriols, triethanolamine, or aliphatic alcohols of higher functionality, e.g. B. pentaerythritol or sorbitol. Conversion products the aforementioned multivalent. Alcohols having from 1 to 3 moles per mole of a 1,2-alkylene oxide can also be used be.

To avoid crystallization in the polyisocyanate compositions obtained, mixtures of two or more compounds with at least three hydroxyl groups in the molecule are used. Suitable Mixtures usually contain at least 20%

509 759/591

3 4

on a molar basis of each compound. Examples of polyaddition of an alkylene oxide in the presence

suitable mixtures are mixtures of glycerine of a basic catalyst such as potassium hydroxide,

and / or trimethylolethane are made with trimethylolpropane, with glycols or primary monoamines,

where the trimethylolpropane in amounts of 50 to On the other hand, you can use polyethers z. B. 70 mole percent is present. Glycols can also be obtained by polyaddition of alkylene oxides in the presence proportionate to the compounds that have at least three of a basic catalyst to a compound with Hydroxyl groups contained in the molecule, added more than two active hydrogen atoms in the molecule are made, thereby improving the stability. Such compounds are e.g. B.

of the product. Examples are ethylene ammonia, polyhydric alcohols such as glycerine,

glycol, diethylene glycol, triethylene glycol or Bu- io hexanetriols, trimethylolethane, or pentaerythritol,

tylene glycol. Amino alcohols, such as monoethanolamines, diethanol

The polyisocyanate masses are amine or triethanolamine, polyamines, such as ethylene

the polyols with the diisocyanate usually with diamine, hexamethylene diamine, diethylene triamine, to-

Temperatures from 20 to HO ⁰ C, preferably of luylenediamine or diaminodiphenylmethane, and

60 to 90 ⁰ C produced. Usually one gives the 15 cane sugar or phenol-formaldehyde condensates,

polyhydric alcohols gradually to diisocyanate, branched polyethers can also be mixed with poly-

however, a solution of the polyols can also be merged with cyclic oxides of the type mentioned above

turn, e.g. B. a solution in an inert organic with cyclic oxides a functionality of more

Solvent. as 2, e.g. B. Diepoxden, Glycidol or 3-Hydroxy-

For the production of polyurethane foams from 20 methyloxacyclobutanes, be made,

These polyisocyanate compositions are used as starting materials The used in the process according to the invention

connections as they are already known. As poly-polyethers, they usually have a molecular weight

hydroxyl compounds can be used, for. B. polyester, from 200 to 6000. Optionally, mixtures can be used

Use polyester amides or polyethers or mixtures of these linear and branched polyethers.

Use connections. 25 Suitable low-boiling liquids that counteract

The polyester or polyester amides can, for. B. from the constituents formed by the polyurethane foam

Dicarboxylic acids and polyhydric alcohols and parts are chemically inert, have a boiling point of

if necessary, smaller quantities diamines or at most 75 ⁰ C, preferably between -40 and

Amino alcohols be produced. Suitable dicarbon - + 50 ° C. Such compounds are e.g. fluorinated

acids are e.g. B. succinic acid, glutaric acid, adipic 3 ° alkanes, such as monofluorotrichloromethane, dibromodifluoro-

acid, suberic acid, azelaic acid or sebacic acid methane, l, l, 2-trichloro-l, 2,2-trifluoroethane, dichloro

as well as aromatic acids such as phthalic acid, isodifluoromethane, monochlorodifluoromethane, dichloromo-

phthalic acid or terephthalic acid. You can also use nofluoromethane, dichlorotetrafluoroethane, trifluoroethyl

Use mixtures of acids. Examples of more bromide or mixtures thereof.

Valuable alcohols are glycols such as ethylene glycol, mixtures of these low-boiling liquids 1,2-propylene glycol, 1,3-butylene glycol, 2,3-butylene with one another and / or with fluorine-free substituted glycol, diethylene glycol, pentamethylene glycol, hexa- or unsubstituted hydrocarbons methylene glycol, decamethylene glycol or 2,2-di- can also be used. These liquids are methyltrimethylene glycol. You can also use others, usually in amounts of 1 to 150%> polyhydric alcohols with more than two hydroxyls, preferably from 25 to 75%> based on the groups in the molecule, such as trimethylol weight of the polyhydroxyl compound,
propane, trimethylolethane, pentaerythritol or glycerine. Water is usually used in amounts from 1 to. Such compounds are used in different amounts according to the weight percent of the polyhydroxyl compound desired hardness of the products when it is used as a blowing agent.
Amounts incorporated. 45 The manufacture of polyurethane foams can

In addition to the polyhydric alcohols and dicarbons, they are carried out according to known methods. So you can acids can also bring along compounds for converting substances continuously or discontinuously that have more than two hydroxyls, mix each other, and the reaction mixture may Carboxyl or secondary or primary amino known additives, such as surface-active groups included, e.g. B. diethanolamine, trimesine 50 bonds, e.g. B. oxyethylated phenols, oxyethylated acid, dihydroxystearic acid or tricarbalylic acid. Fatty alcohols such as oleyl alcohol or sulfated oil examples for diamines or amino alcohols leading to methyl acid esters, or alkyl or aryl polysiloxanes Production of polyester amides or their block copolymers with alkylene oxides, are ethylenediamine, hexamethylene and catalysts such as tertiary amines or soluble diamine, monoethanolamine, phenylenediamine or organic metal compounds, e.g. B. Dibutyltin Benzidine. dilaurate, tin (II) octoate, lead acetate or iron or

The manganese acetylacetonates used in the process according to the invention contain. Often you can Polyesters and polyester amides usually have beneficial mixtures of catalysts using a molecular weight of 200 to 5000, and it is about- Other suitable additives are e.g. B. Foam cradles Hydroxyl end group h. 60 stabilizers, such as ethyl cellulose, flame retardants

Examples of the solid finish in the process according to the invention, such as / S-trichloroethyl phosphate or anti-

Polyethers used are hydroxyl end groups monoxide, plasticizers such as dialkyl phthalates, color

containing polymers and copolymers of eye-substances and antioxidants, such as tert-butyl-

metallic oxides, such as 1,2-alkylene oxides, e.g. B. ethylene catechol or sterically hindered phenols,

oxide, epichlorohydrin, 1,2-propylene oxide, 1,2-butylene 65 To prove that when using a

oxide or 2,3-butylene oxide, oxacyclobutane, sub- settlement product of polyisocyanates with alcohol

substituted oxacyclobutanes or tetrahydrofuran. Such combinations according to the invention compared

Polyethers can be linear polyethers, as they are e.g. B. those with only one or two alcohols one

Corresponding comparative tests were carried out to achieve a significant improvement in the shelf life of the products carried out, using the reaction product according to the German U.S. Patent 1,112,285 (Product A), a product made using two polyols

(Product B), and a product made using three polyols (Product C). the end The table below shows that the product according to the invention is still stable after 21 days and remains stable beyond this time.

product Polyols used Initial ratio
• of hydroxyl groups
to isocyanate groups Crystallization time
of the product A.
B { Trimethylol propane
3.74 moles of trimethylol propane
1.0 mol glycerine
3.5 moles of trimethylol propane
3.5 moles of glycerin
2.0 moles of diethylene glycol
1.0 mole of hexanetriol 0.28
} 0.26
I 0.28 ITag
6 days
still stable after 21 days

The invention is further illustrated by the following examples. Parts and percentages relate to weight.

Conversion product 1

4613 parts of an 80:20 mixture of 2,4- and 2,6-toluylene diisocyanate are stirred and ^{heated to 75 °} C. and a warm homogeneous mixture of 441 parts of trimethylolpropane and 151 parts of glycerol is added dropwise over the course of 2 hours. The temperature of the reaction mixture is kept at 75 to 80 ° C. during the addition. After the addition of the polyhydroxy compounds has ended, the reaction mixture is heated to 75 to 80 ° C. for a further 2 hours. The product is then cooled and filtered through a sieve with a mesh size of 0.21 mm to remove traces of insoluble polymer. 5086 parts of a clear, somewhat viscous liquid with 30.35% reactive isocyanate groups are obtained.

Conversion product 2

174 parts of an 80:20 mixture heated to 75 ° C of 2,4- and 2,6-tolylene diisocyanate were added dropwise with stirring with a homogeneous warm mixture of 10.3 parts of trimethylolpropane, 7.1 parts of glycerol and 4.5 parts of 1,2,6-hexanetriol brought to implementation according to reaction product 1. The product is a clear, viscous liquid with 30.5% reactive isocyanate groups.

Conversion product 3

4610 parts of toluene diisocyanate are mixed with a homogeneous mixture of 273.9 parts of trimethylolpropane, 188 parts of glycerol and 140.7 parts of diethylene glycol according to reaction product 1 for the reaction brought. 5138 parts of a clear, somewhat viscous liquid with 30.5% reactive are obtained Isocyanate groups.

example 1

100 parts chloroethyl Trijö-a liquid polyether (prepared by addition of propylene oxide with trimethylol propane to give a product with the molecular weight of 310, a hydroxyl number of 543 mg KOH / g and a viscosity at 25 ⁰ C of 17 poise) with 15 parts, 1 part of dibutyltin dilaurate and 1 part of a siloxane-oxyalkylene block copolymer mixed.
A second premix is prepared by stirring 60 parts of monofluorotrichloromethane into 165 parts of the reaction product 3.

The two premixes are combined with one another by stirring vigorously for 25 seconds. The mixture is then poured into a mold.

It foams to a foam with a fine structure and good rigidity within 90 seconds. The density of the foam is 0.024 g / cm ³ .

Example 2

According to Example 1, a polyether premix is used

manufactured.
A second premix is made by incorporating

of 40 parts of monofluorotrichloromethane in 165 parts of the reaction product 2 prepared.
The two premixes are mixed together by stirring vigorously for 25 seconds.

Here they start to foam. A fine, hard foam with a density of 0.028 g / cm ^{3 is obtained} .

B e i s ρ i e 1 3

100 parts of the polyether of Example 1 are mixed with 1 part of the siloxane-oxyalkylene block copolymer of Example 1, 0.2 part of dibutyltin dilaurate and 1 part of dimethylcyclohexylamine were added.

A second premix consists of 137 parts of the modified tolylene diisocyanate of reaction product 1 and 18 parts of monofluorotrichloromethane.

The two premixes are mixed together by stirring vigorously for 15 seconds.

The mixture reacts to form a rigid foam with a fine-cell structure and a density of 0.034 g / cm ³ .

Example 4

100 parts of the liquid polymer which has been prepared by addition of propylene oxide with triethanolamine (molecular weight 378, hydroxyl number 445 mg KOH / g, viscosity at 25 ⁰ C for 2.5 poise), are mixed with 6 parts water, 30 parts of tri-.beta. chloroethyl phosphate, 12 parts of triethanolamine and 4 parts of a propylene oxide-ethylene oxide block copolymer were added.

A second premix consists of 242 parts of settlement product 1 reacted. That

of the modified toluene diisocyanate of the order product is a somewhat viscous liquid with a

Settlement product 1, mixed with 33.4 parts of mono content of 30.5% reactive isocyanate groups.

fmortrichloromethane. _R. -17

The two premixes are used for 15 seconds S Example /

stirred together. Foaming takes place, and 165 parts of a mixture of 65 parts of mono-

receives a foam with a fine structure and a fluorotrichloromethane and 100 parts of the oxy-

Density of 0.027 g / cm ³ . propylation of an 80:20 mixture of 2,4- and

2,6-tolylenediamine (hydroxyl number 464 mg KOH / g)

B e 1 s ρ 1 e 1 5 ₁₀ obtained product are 30 parts of tri - ^ - chloroethyl

100 parts of a liquid polyether, which is replaced by phosphate, 1 part dibutyltin dilaurate and 1 part

Addition of propylene oxide to sorbitol produces siloxane-oxyalkylene block copolymers.

has been (hydroxyl number 495 mg KOH / g, viscosity then this mixture is made with 120 parts

7500 cP at 25 ⁰ C) are mixed with 30 parts tri-jS-chloro-4 of the reaction product and the mixture

ethyl phosphate, 1 part of the siloxane-oxyalkylene block 15 stirred vigorously for 20 seconds, whereupon it is within

copolymers of Example 1, 1 part of dibutyltin foams for 2 minutes to form a fine-celled product,

dilaurate and 1 part 4-dimethylaminopyridine have good strength after hardening. the

mixes. The density of the foam is 0.025 g / cm ³ .

The second premix consists of 121 parts of the. · 1 ο

modified tolylene diisocyanate of the implementation 20 üeispie

Product 1, mixed with 50 parts of monofluoro 100 parts of an oxypropylated triol from MoIe-

trichloromethane. Weight 4000, 3 parts glycerin and 86.5 parts

The two premixes are mixed with the reaction product 4 for 30 seconds.

Stir mixed together for 20 seconds. announce with the help of a high-speed stirrer

The foaming lasts 90 seconds, the foam is stirred for 25 (1200 rpm). A

no longer sticky after 2V4 minutes. The foam activator solution of 3.5 parts of water, 1.0 part

material is rigid and of a fine structure, and it has triethylenediamine and 1.0 part of a siloxane oxy-

a density of 0.032 g / cm ³ . injected alkylene block copolymer and that

Mixture stirred for a further 10 seconds. Then will

In the case of 1 6 30 pour the mixture into a mold. The resulting

Due to the condensation of 14 moles of trimethylolpropane foam has a high modulus, and he

with 6 moles of adipic acid a polyester is suitable as a cushioning material for the production of

A hydroxyl number of 636 mg KOH / g, an acid number on shop signs, etc. The density of the foam

of 2.7 mg KOH / g and a viscosity at 25 ° C is about 0.043 to 0.046 g / cm ³ ,

of 382 poise made in a known manner. 35 t> · · 1 q

130 parts of this polyester are mixed with 30 parts e 1 s ρ 1 e i y

Tri-jS-chloroethyl phosphate and 9 parts of a 66% strength The method according to Example 8 is carried out with addition

aqueous solution of dimethylbenzylamine lactate ver of 10 parts of monofluorotrichloromethane to the ur-

mixes. initial reaction mixture repeated. The GE-

In a second premix, 297 parts of the foamed product have a high modulus and a modified tolylene diisocyanate's conversion density of 0.035 g / cm ³ .
Product 1 and 66 parts of monofluorotrichloromethane _R. . . .
with 5 parts of a siloxane-oxyalkylene mixed poly Example lü
merisats homogenized. This copolymer is 100 parts of an oxypropylated triol from mol by reacting a) a methyl hydrogen 45 kulargewicht 6000, 0.3 part of tin (II) octoate and polysiloxane (produced by joint hydrolysis 67.6 parts of the reaction product 4 are 30 Sevon 3 mol Methyldichlorosilane, 15 mol of dimethyl künden with the aid of a high-speed stirrer dichlorosilane and 2 mol of trimethylchlorosilane) with b) (1200 rpm) stirred. In the mixture, a polyether with a molecular weight of 1529 in an activator solution of 3.5 parts of water, 0.5 parts of the presence of tin (II) octoate as a catalyst in 5 ° triethylenediamine and 1.0 part of a siloxane oxy is prepared in a manner known. The polyether is injected as an alkylene block copolymer. The usual way of oxyalkylating commercialization is to stir for a further 10 seconds and then pour the amount of isooctanol with a mixture of the same into a mold. The resulting foam parts by weight of ethylene oxide and propylene oxide have a high modulus, and it is suitable as a posed. 55 Padding material for making shop signs

The two premixes are stirred together for 10 seconds, etc. It has a density of about 0.043 to 0.046 g / cm ^3. The mixture is then converted into “.
poured a mold in which it becomes a fine-cell Example 11
Foam with a density of 0.024 g / cm ^3, 100 parts of an oxypropylated triol vom Moleschaumed. The foam has good strength and 60 kular weight 4000, 3 parts glycerin, 69.2 parts of the compression resistance. Reaction product 4 and 10.7 parts of a 80:20 _TT j 1 α mixture of toluene-2,4- and 2,6-diisocyanates Reaction product 4 _{are 30 seconds with the aid of a} high-speed

2000 parts of an 80:20 mixture of 2.4 and stirrer (1200 rpm) were stirred. In the mixture becomes

2,6-tolylene diisocyanate are activated with a homogeneous 65 the activator solution described in Example 8

Mixture of 107.9 parts of trimethylolpropane, 74.2 parts injected, the mixture stirred for a further 10 seconds

len glycerin, 48.75 parts of diethylene glycol and 41.1 parts and then poured into a mold. The resulting

len crude 1,2,6-hexanetriol (75.7%) according to Um foam has a high modulus, and he

is suitable for making shop signs and as upholstery material. The density of the foam is about 0.04 g / cm ³ .

Claims (2)

Patent claims: 1. Process for the production of polyurethane foams by reacting polyhydroxyl compounds with NCO groups containing reaction products of polyisocyanates with trihydric alcohols in the presence of a reactive or inert blowing agent, characterized in that the NCO group-containing reaction products of polyisocyanates with trihydric alcohols, a product is used which, through conversion of 10 to 40% 10 of the isocyanate groups of a tolylene diisocyanate with a mixture of two or more, at least three OH groups containing aliphatic alcohols has been obtained. 2. The method according to claim 1, characterized in that a product is used which by reacting 10 to 40% of the isocyanate groups of a toluene diisocyanate with a at least 20 mol percent of the mixture components containing mixture of two or more, at least three OH groups containing alcohols has been obtained. Considered publications:
German Auslegeschrift No. 1112 285;
"Bayer-Kunststoffe", 1959, "Desmodur L". 509 759/591 12.65 © Bundesdruckerei Berlin