JPH01203420A - Production of urethane foam - Google Patents

Abstract

PURPOSE:To improve hardness in obtaining polyurethane foam by reacting an organic polyisocyanate with a polyol in the presence of a blowing agent, catalyst, etc., by using a specific polyol. CONSTITUTION:An organic polyisocyanate (preferably 2,4-tolylene diisocyanate) is reacted with a polyol containing a polymer polyol obtained by polymerizing an ethylenic unsaturated monomer (preferably ethylenic unsaturated nitrile, etc.) in a polyol (preferably polyether polyol) and an organic acid (preferably >=5C aliphatic or aromatic mono- or polycarboxylic acid) in the presence of a blowing agent, a catalyst and optionally other auxiliaries to produce polyurethane foam suitable for automobiles, furniture, etc. The amount of the polymer polyol added is preferably >=100pts.wt. based on the all polyols and the amount of the organic acid is preferably 0.2-3pts.wt.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a method for producing polyurethane foam.

[Prior Art] Methods of increasing the hardness of polyurethane foam include adding a crosslinking agent, increasing foam density, and adding a polymer polyol prepared by polymerizing an ethylenically unsaturated monomer in a polyol. be.

[Problems to be Solved by the Invention] However, these methods have advantages and disadvantages. That is, in the method of adding a crosslinking agent, the amount of crosslinking agent added and the foam elongation rate are in a reciprocal relationship, and this method is impractical when formed into a foam. In addition, polyurethane foams other than so-called cold-cure foams have the problem that when a crosslinking agent is added, the foams shrink during production. The method of increasing the foam density causes an increase in the weight of the foam, and is therefore undesirable for applications such as automobiles and furniture. The method of adding a polymer polyol has problems, such as increasing the viscosity of the polyol and polymer polyol, increasing the density of the polyurethane foam, and requiring special foaming machine equipment.

[Means for solving the problem] As a result of study, the present invention was arrived at. That is, the present invention provides a method for producing polyurethane foam by reacting an organic polyisocyanate and a polyol in the presence of a blowing agent, a catalyst, and optionally other auxiliary agents, wherein the polyol is ethylenically unsaturated in the polyol. This is a method for producing polyurethane foam characterized by containing a polymer polyol obtained by polymerizing monomers and an organic acid.

The organic acids used in the present invention include aliphatic mono- or polycarboxylic acids (formic acid, acetic acid, propionic acid, butyric acid, caproic acid, caprylic acid, capric acid, octylic acid,
1-1 carbon atoms such as lauric acid and 2-ethylhexanoic acid
Monocarboxylic acids with 5 linear or side chains; saturated or unsaturated polycarboxylic acids such as schuvic acid, malonic acid, geltaric acid, adipic acid, maleic acid, etc.), aromatic mono- or polycarboxylic acids (benzoic acid, phthalic acid, etc.)
Aliphatic oxycarboxylic acids (malic acid, tartaric acid, citric acid, glycolic acid, glyceric acid, dioxyadipic acid,
trioxygeltaric acid), aromatic oxycarboxylic acids (such as salicylic acid) and halogen-, nitro-, nitrile-, acyl- and alkyl-substituted versions of these acids (monochloroacetic acid, etc.).

dichloroacetic acid, β-bromopropionic acid, and o-
(or m7, -p=) Carboxylic acids in which the hydrogen of an aliphatic group (or aromatic group) is replaced with a halogen, such as chlorobenzoic acid; organic sulfonic acids such as alkanesulfonic acids (methanesulfonic acid, etc.), benzene Halides of organic acids such as sulfonic acid, p-toluenesulfonic acid, α- or β-sulfonic acid, etc.2 Chlorides, bromides, etc. of each of the above-mentioned carboxylic acids, such as acetyl chloride, propionyl chloride, butyroyl bromide, benzoyl bromide etc. can be used. Among the above organic acids, preferred are carboxylic acids and sulfonic acids, and particularly preferred are aliphatic or aromatic mono- or polycarboxylic acids having 5 or more carbon atoms.

Based on an ion dissociation chamber at 25°C for organic acids, <PKa2> is usually 1 to 6. Preferably it is 1.7-4.

As the polyol used in the production of the polymer polyol in the present invention, those commonly used for polyurethane are used. Examples include polyether polyol, polyester polyol, castor oil, and the like.

As one polyether polyol, polyhydric alcohol,
Examples include compounds having a structure in which alkylene oxide is added to a polyfunctional compound containing an active hydrogen atom, such as polyhydric phenol or polycarboxylic acid. The polyhydric alcohol mentioned above is
Ethylene glycol, propylene glycol, 1,4-
Dihydric alcohols such as butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, and trivalent or higher polyhydric alcohols such as glycerin, trimethylolpropane, pentaerythritol, sorbitol, sucrose; as polyhydric phenols Examples include polyhydric phenols such as pyrogallol and hydroquinone, as well as bisphenols such as bisphenol A; and condensates of phenol and formaldehyde (novolac), such as the polyphenols described in US Pat. No. 3,265,641. Also, examples of amines include ammonia; mono-, di-, and triethanolamine;
Alkanolamines such as isopropanolamine and aminoethylethanolamine; C0- to C2(+alkylamines; C2 to C6 alkylene diamines such as ethylene diamine, propylene diamine, hexamethylene diamine, polyalkylene polyamines such as diethylene triamine, triethylene Aliphatic amines such as tetramine; aniline, phenylenediamine, diaminotoluene, xylylenediamine, methylenedianiline,
Examples include diphenyl ether diamine and other aromatic amines; alicyclic amines such as isophorone diamine and cyclohexylene diamine; aminoethylpiperazine and other heterocyclic amines described in Japanese Patent Publication No. 55-21044. Examples of polycarboxylic acids include aliphatic polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, maleic acid, and dimer acid, and aromatic polycarboxylic acids such as phthalic acid, terephthalic acid, and trimellitic acid. Two or more kinds of the above-mentioned active hydrogen atom-containing compounds can also be used. Among these, polyhydric alcohols are preferred. Examples of the alkylene oxide to be added to the active hydrogen atom-containing compound include propylene oxide (abbreviated as PO), ethylene oxide (abbreviated as EO), butylene oxide, and tetrahydrofuran. The alkylene oxides may be used alone or in combination of two or more, and in the latter case, block addition or random addition may be used. Preferred among these alkylene oxides are PO and EO. Examples of polyester polyols include condensed polyester polyols obtained by reacting low-molecular-weight polyols (such as the aforementioned dihydric alcohols, trimethylolpropane, and glycerin) with dicarboxylic acids (such as the aforementioned polycarboxylic acids), and lactones (such as ε-caprolactone). Examples include polyester polyols obtained by ring-opening polymerization of ). Preferred among these polyols are polyether polyols. The oH-v of Kowara polyol is usually 20
-70, more preferably 25-60.

As the polymer polyol used in the present invention, those commonly used in polyurethane foams can be used. This polymer polyol is obtained by polymerizing an ethylenically unsaturated monomer in the above polyol in the presence of a radical initiator. Examples of ethylenically unsaturated monomers include ethylenically unsaturated nitriles [(meth)acrylonitrile, etc.]
, ethylenically unsaturated carboxylic acids and their derivatives [(meth)acrylic acid, (meth)acrylate, etc.], aliphatic hydrocarbon monomers [ethylene, propylene, carbon atoms from 4 to
20 α-olefins, etc.], aromatic hydrocarbon monomers [
styrene, methylstyrene, etc.], and other vinyl monomers (nitrostyrene, vinyl acetate, etc.).

Preferably, it is an ethylenically unsaturated nitrile alone or a mixture with an aromatic hydrocarbon monomer.

A radical initiator is usually used for polymerization, and examples of the radical initiator include azo compounds such as 2,2'-azobisisobutyronitolyl (AIBN), azodiester polyols, and t-butylperoxy-2- Peroxides such as ethylhexanoate, t-butylperbivalate, and other peroxides described in Japanese Patent Application No. 199160/1983, or persulfates, perborates, and persuccinates. etc. can be used. Among these, preferably A
It is IBN.

If necessary, chain transfer agents such as alkyl mercaptans (dodecyl mercaptan, mercaptoethanol, etc.), alcohols (methanol, 2-butanol, etc.), halogenated hydrocarbons (carbon tetrachloride, carbon tetrabromide, etc.),
(chloroform, etc.), enol ethers described in JP-A-55-31880, and the like. In the present invention, the amount of ethylenically unsaturated monomer added to the polyol is usually 5 parts per 100 parts of the polyol.
-60 parts, preferably 10-40 parts.

A method for producing a polymerized polyol from a polyol and an ethylenically unsaturated monomer may be a known method, such as a method in which an ethylenically unsaturated monomer is graft-polymerized in a polyol in the presence of a polymerization catalyst such as a radical initiator. (U.S. Patent No. 3383351, Japanese Patent Publication No. 39”24737, Japanese Patent Publication No. 47-47999, Japanese Patent Publication No. 15894-1987)
Alternatively, there is a method (Japanese Patent Publication No. 47-47597) in which a polymer obtained by previously polymerizing the above monomers and a polyol are graft-polymerized in the presence of a radical initiator. The former is preferred.

Other polyols can be used together with the polymer polyol if necessary. As this polyol, those used in the production of polymer polyols can be used.

As the organic polyisocyanate used in the present invention, those commonly used for polyurethane are used.

For example, aromatic polyisocyanates having 6 to 20 carbon atoms (excluding the carbon in the NGO group) [2,4- and/or 2,4- and/or
6-Dylene diisocyanate (TDI), TDI manufactured by @
, 2,4'- and/or 4,4'-diphenylmethane diisocyanate (MDI), crude MDI [crude diaminophenylmethane (a condensation product of formaldehyde and an aromatic amine (aniline) or a mixture thereof, didiaminodiphenylmethane and a small amount (For example, 5-20% heavy view)
Phosgenated products of (polyaryl polyisocyanate (PAPI), etc.): Aliphatic polyisocyanates having 2 to 18 carbon atoms [hexamethylene diisocyanate, lysine diisocyanate, etc.]: 4 to 4 carbon atoms 15 alicyclic polyisocyanate (isophorone diisocyanate, dicyclohexyl diisocyanate, etc.): Aroaliphatic polyisocyanate having 8 to 15 carbon atoms [xylylene diisocyanate, etc.]
: and modified products of these polyisocyanates (modified products containing urethane group, carbodiimide group, allophanate group, urea group, biuret group, uretdione group, uretonimine group, isocyanurate group, oxazolidone group, etc.): and Japanese Patent Application No. 59-199160 Examples include polyisocyanates other than those described in the above publications and mixtures of two or more thereof. Among these, preferred are 2,4- and 2,6-TD and mixtures of these isomers, 2,4'- and 4,4'-MDI and mixtures of these isomers, and Urethane groups, carbodiimide groups, allophanate groups, urea groups, biuret groups, uretdione groups, uretonimine groups, isocyanurate groups derived from these polyisocyanates,
It is a modified polyisocyanate containing an oxazolidone group, and the NC0% is usually 15 to 55%, preferably 20 to 5.
It is 0%.

As the foam stabilizer, one for soft urethane foam is usually used. For example, L-540 (Nippon Unicar Co., Ltd.)
(manufactured by Toray Silicone Co., Ltd.), 5R-190, 5RX-294A (manufactured by Toray Silicone Co., Ltd.), and the like.

Any known catalyst can be used. Specifically metal salts of carboxylic acids, such as sodium acetate, lead octylate, zinc octylate, cobalt naphthenate, etc.; alkoxides and phenoxides of alkali and alkaline earth metals, such as sodium methoxide, sodium phenoxide, Quaternary ammonium bases, such as tetraethylammonium hydroxy, etc.; Imidazoles, such as imidazole, 2
-Ethyl-4-methylimidazole, etc.: Examples include organometallic compounds such as tin and antimony, such as tetraphenyltin and tributylantimony oxide. Among these, preferred are organometallic compounds such as tin and antimony, and tertiary amines.

As the blowing agent, those commonly used for polyurethane foam can be used. Examples are water, freon, and methylene chloride.

Flame retardants and colorants can also be added as additives if necessary.

A suitable addition amount in the present invention will be described.

The amount of organic acid added is usually 0.1 to 5 parts, preferably 0.2 to 3 parts, per 100 parts of polyol. 0.1
Hardness is less than 5 parts 1. The impact resilience of y, B, and i forms decreases. Although the organic acid may be added during the production of the monopolymer polyol, it is preferably added to the polyol component during the production of polyurethane foam. The amount of polymer polyol added to polyol is 100% of total urine
The amount is usually 80 parts or more, preferably 100 parts or more.

If the hardness is less than 80 parts, the hardness of the foam will not be as high as that of a boat. The NGO index used in the present invention is usually 70-110, preferably 75-105.

. The number of parts of foam stabilizer used is 3 parts per 100 parts of polyol.
parts, preferably 0.05 to 2 parts. Outside this range, an appropriate curing time cannot be obtained. The amount of blowing agent used is not particularly limited, but the amount of water used is usually 2 to 6 parts, preferably 3 to 5 parts, per 100 parts of polyol. The amount of additives used if necessary is usually 0 to 15 parts, preferably 5 to 1 part, per 100 parts of polyol.
It is 0 copies.

The production method according to the present invention can be carried out by one of the so-called slab, pot cure, and cold cure methods, but among these, the slab table and hot cure method are preferable, and the hot cure one method is particularly preferable. Although described in detail, the present invention is not limited to these embodiments.

The parts are by weight. The composition, foaming recipe, production conditions, etc. of the polyol of this example will be explained.

Polyol A---Glycerin is polymerized with PO and EO in the presence of a catalyst by a conventional method, and the H-V is 56 and the EO content is 10% based on the entire polyol.

Polymer polyol A---PO to glycerin under catalyst
was polymerized by a conventional method and 0H-V was 45. In 100 parts of 0F (-V is 56), 12.5 parts of acrylconitrile and 12.5 parts of styrene were polymerized with 3 parts of AIB No.

Polymer polyol B--In 100 parts of polyol A, 32 parts of acrylonitrile and 8 parts of styrene were added to AIBN.
Example 1 Polymer polyol A was used as the polymer polyol and octylic acid was used as the organic acid to prepare a flexible polyurethane foam according to Table 1. The results are listed in Table 1. It can be seen that the hardness is superior to Comparative Example 1 of the prior art.

Example 2 A flexible polyurethane foam was produced using polymer polyol A as the polymer polyol and octyl acid as the organic acid. The results are listed in Table 1.

It can be seen that the hardness is superior to Comparative Example 1 of the prior art.

Example 3 A flexible polyurethane foam was produced using polymer polyol B as the polymer polyol and lauric acid as the organic acid. The results are listed in Table 1.

It can be seen that the hardness is superior to Comparative Example 1 of the prior art.

Example 4 A flexible polyurethane foam was prepared using polymer polyol/L/B as the polymer polyol and lauric acid as the organic acid. The results are listed in Table 1. It can be seen that the hardness is superior to Comparative Example 1 of the prior art.

Comparative Example 1 A flexible polyurethane foam was produced in the same manner as in Example 1 except that no organic acid was used in Example 1. The results are listed in Table 1.

[Effects of the invention] Compared to conventional manufacturing methods, the polyurethane manufacturing method of the present invention can increase the hardness of the foam without deteriorating physical properties other than hardness, and also has excellent workability because the raw material has a low viscosity. ing.

Since it has the above-mentioned effects, it has a remarkable effect in applications such as automobiles and furniture.

Claims (1)

[Claims] 1. A method for producing polyurethane foam by reacting an organic polyisocyanate and a polyol in the presence of a blowing agent, a catalyst, and optionally other auxiliary agents, in which the polyol is an ethylenic inorganic compound in the polyol. A method for producing a polyurethane foam, comprising a polymer polyol obtained by polymerizing a saturated monomer and an organic acid. 2. The method according to claim 1, wherein the organic acid is a carboxylic acid and/or a sulfonic acid.