JPH03239716A - Composition for forming flexible polyurethane foam and its production - Google Patents

Abstract

PURPOSE:To produce the title composition which has improved foaming stability and can give a foam resistant to disintegration and cracking by mixing an organic polyisocyanate with a specified polyol, a catalyst, a blowing agent and a foam stabilizer. CONSTITUTION:A polyol mixture is obtained by mixing 30-70% polyether polyol having a functionality of 3-4, a mol.wt. of 800-1400 per hydroxyl group and a polyoxyethylene chain content of 30-70wt.%, based on the total mol.wt., with 70-30wt.% polyether polyol having a functionality of 3-4, a mol.wt. of 1200-2400 per hydroxyl group and a polyoxyethylene chain content of 20wt.% or below based on the total mol.wt. and/or polyether polyol having a functionality of 2-3, a mol.wt. of 200-500 per hydroxyl group and polyoxypropylene chains. 100 pts.wt. this polyol mixture is reacted with an organic polyisocyanate in an amount of 70-120 in terms of an NCO index at 20-50 deg.C in the presence of 2-8 pts.wt. blowing agent, 0.01-3 pts.wt. catalyst and a foam stabilizer.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to flexible polyurethane foam-forming compositions and methods for making flexible polyurethane foams.

More specifically, the present invention relates to a composition for forming a hot-molded polyurethane foam having low foam hardness and suitable for automobile seat cranbon, and a method for producing the foam.

[Prior Art] Methods for lowering the hardness of polyurethane foam include lowering the number of functional groups in polyol, using fluorocarbons as a blowing agent, and using polyols with a large number of polyoxyethylene chains (for example, Japanese Patent Publication No. 4B-1999). No. 28793,
Special Publication No. 58-3488, Special Publication No. 53-13700,
Special Publication No. 5B-43247 and Special Publication No. 54-173
60 publications).

[Problem to be solved by the invention] However, these methods have advantages and disadvantages.

That is, the method of lowering the number of functional groups in the polyol increases the curing time of the foam and significantly worsens the compression set, making it impractical. The method of using fluorocarbons as a blowing agent has environmental problems. In the method of using polyol with many polyoxyethylene chains, when molded polyurethane foam is molded by the one-shot method,
Foaming stability is poor, resulting in foam collapse and cracking, making it impossible to obtain the desired polyurethane foam molded product.

[Means for Solving the Problems] The present inventors solved these problems and, as a result of intensive studies on compositions and foam manufacturing methods capable of forming soft polyurethane foams with foam hardness, the present invention has been developed. Reached. That is, the present invention provides a flexible polyurethane foam-forming composition comprising an organic polyisocyanate, a polyol, a catalyst, a blowing agent, and a foam stabilizer, in which the polyol (a) has a functional group number of 2 to 4 and a molecular weight per hydroxyl group of 800 to 1400; (b) (b-1) a polyether polyol in which the polyoxyethylene chain accounts for 30 to 70% by weight of the total molecular weight; A polyether polyol with chains of 5 to 20% by weight of the total molecular weight; (b-2) a polyoxyethylene chain with 3 to 4 functional groups, a molecular weight of 120 to 2,400 per hydroxyl group, and a polyoxyethylene chain of 20% by weight or less of the total molecular weight; and/or (b-3) a polyether polyol having a functional group number of 2 to 3, a molecular weight per hydroxyl group of 200 to 500, and a polyoxypropylene chain,
The weight ratio of (a) and (b) is (a)/(b)=30/
A flexible polyurethane foam-forming composition characterized in that the ratio is 70-70/30: and an organic polyisocyanate and a polyol are reacted in the presence of a catalyst, a blowing agent and a foam stabilizer to produce a flexible polyurethane foam. In the method of
(b) (b-1)
Number of functional groups: 3-4, molecular weight per hydroxyl group: 600-11
00 and polyoxyethylene chains are 5 to 20% by weight of the total molecular weight, (b-2) number of functional groups is 3 to 4, and molecular weight per hydroxyl group is 1200 to 2400.
and/or (b-3) a polyether polyol with a polyoxyethylene chain of 20% by weight or less of the total molecular weight;
Number of functional groups: 2-3, molecular weight per hydroxyl group: 200-50
0, it consists of a combination with a polyether polyol which is a polyoxypropylene chain, and the weight ratio of (a) and (b) is (
This is a method for producing a flexible polyurethane foam characterized by using a foam having a ratio of a)/(b) = 30/70 to 70/30.

Examples of the polyol (a) used in the present invention include compounds having a structure in which an alkylene oxide is added to a compound having an active hydrogen atom having 2 to 4 functional groups (for example, alcohols and amines). Alcohols include ethylene glycol, propylene glycol,
1. Examples include dihydric alcohols such as 4-phthanediol, 1,6-hexanediol, diethylene glycol, and neopentyl glycol, and trihydric and tetrahydric alcohols such as glycerin, trimethylolpropane, and pentaerythritol. Examples of amines include ammonia; mono-di and alkanolamines such as triethanolamine, isopropanolamine, and aminoethylethanolamine; C1 to C21! Alkylamines; C2-Co alkylene diamines such as ethylene diamine and hexamethylene diamine; polyalkylene polyamines such as diethylene triamine and triethylene tetramine; aliphatic amines such as aniline, phenylene diamine, diaminotoluene, xylylene diamine, methylene dianiline , aromatic amines such as diphenyl ether diamine; isophorone diamine,
Alicyclic amines such as cyclohexyl/diamine; aminoethylpiperazine, heterocyclic amines described in Japanese Patent Publication No. 55-21044, and the like. Two or more of these active hydrogen atom compounds may be used in combination. Among these, alcohols are preferred.

As the alkylene oxide to be added to the above active hydrogen atom compound, ethylene oxide (hereinafter abbreviated as EO)
, propylene oxide (hereinafter abbreviated as PO), 1. 2
-1. 3-1. Examples include 4-2.3-butylene oxide and the like, and combinations of two or more thereof, preferably a combination of EO and PO, and the addition form is random addition of PO and EO.

The number of functional groups in polyol (a) is 2 to 4, preferably 2,
5 to 3.5. If the number of functional groups is less than 2, the compression set will be poor and the curing time will be long.

Moreover, if it exceeds 4, the foam hardness, which is the object of the present invention, will not become soft.

The molecular weight per hydroxyl group of polyol (a) is 800~
1400. Preferably it is 900-1300. If the molecular weight per hydroxyl group is less than 800, the foam will collapse, and if it exceeds 1,400, the compression set will be poor and the curing time will be longer.

The polyoxyethylene chains of polyol (a) account for 30-70% by weight, preferably 40-60% by weight of the total molecular weight. If it is less than 30% by weight, a urethane foam with a soft foam hardness, which is the object of the present invention, cannot be obtained;
The form collapses when exceeded.

(b-1) number of functional groups in polyol (b) 3 to 4;
As a polyether polyol with a molecular weight of 600 to 1100 per hydroxyl group and a polyoxyethylene chain of 5 to 20% by weight of the total molecular weight, an alkylene oxide is added to a compound having an active hydrogen atom with a functional group number of 3 to 4. Examples include compounds with a structure. Examples of compounds having an active hydrogen atom having a functional group number of 3 to 4 include trihydric and tetrahydric alcohols described in section (a), and amines having a functional group number of 3 to 4, such as ammonia; Alkanolamines such as; C2-C6 alkylene diamines such as ethylene diamine and hexamethylene diamine; Aliphatic amines such as polyalkylene polyamines such as diethylene triamine and triethylene tetramine; aminoethyl piperazine, described in Japanese Patent Publication No. 55-21044 Examples include heterocyclic amines. Two or more of these active hydrogen atom compounds may be used in combination. Among these, alcohols having 3 to 4 functional groups are preferred.

Examples of the alkylenoxide to be added to the compound having an active hydrogen atom include those described in (a), and a combination of EO and PO is preferred.

Addition formats include block and/or random addition. Preferably (1) a PO and EO silane adduct; (2) a PO pro-adduct in (1);
(3) Block adduct in the order of EO-PO-EO-PO, (4) EO-capped molecular end, (
5) It is a pro-adduct in the order of EO-PO.

(b-2) Number of functional groups: 3 to 4, molecular weight per hydroxyl group: 1
As polyether polyols having a molecular weight of 200 to 2400 and a polyoxyethylene chain of 20% by weight or less of the total molecular weight,
Examples include compounds having a structure in which an alkylene oxide is added to a compound having an active hydrogen atom having 3 to 4 functional groups. Examples of the compound having an active hydrogen atom with a functional group number of 3 to 4 include those described in the section (b-1). The same is also preferred.

Examples of the alkylene oxide to be added to the compound having an active hydrogen atom include those described in (a), preferably PO alone or a combination of EO and PO.

The addition format is also the same as (b-1).

(b-3) Number of functional groups: 2 to 3, molecular weight per hydroxyl group: 2
Examples of polyether polyols having a polyoxypropylene chain and having a polyoxypropylene chain having a polyoxypropylene chain include compounds having a structure in which PO is added to a compound having an active hydrogen atom having 2 to 3 functional groups (for example, alcohols and amines).

Examples of alcohols include dihydric alcohols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and neopentyl glycol, and glycerin.
Examples include trihydric alcohols such as trimethylolpropane. Amines include ammonia; alkanols such as mono- and triethanolamine, impropaturamine, and aminoethylethanolamine;
! Rareamines; Aliphatic amines such as C+ to C2,1 alkyl amines; Aromatic amines such as aniline, phenylene diamine, diaminotoluene, xylylene diamine, methylene dianiline, diphenyl ether diamine: isophorone diamine, cyclohexylene diamine, etc. Cycloaliphatic amines: aminoethylpiperazine,
Examples include heterocyclic amines described in Japanese Patent Publication No. 55-21044. Alcohols are preferred.

Based on the weight of (b), the amount of (b-1) is usually 40~
95%, preferably 50-90%.

If it is less than 40%, the foam will take a long time to harden, making it impractical; if it exceeds 95%, foaming stability will deteriorate.

The amount of (b-2) is usually 0 to 60%, preferably 5 to 40%.
%. If it exceeds 60%, the curing time of the foam becomes long, making it impractical.

The amount of (b-3) is usually 0 to 17%, preferably 0 to 15%.
%. If it exceeds 17%, the curing time of the foam becomes long, making it impractical.

(b) usually has an average number of functional groups of 2 to 4, preferably 2.5.
~3.5, molecular weight per hydroxyl group is usually 200-24
00°, preferably from 400° to 2000°, and the polyoxyethylene chains account for less than 20% by weight of the total molecular weight, preferably less than 15% by weight of the total molecular weight.

If the average number of functional groups in (b) is less than 2, the compression set will be poor and the curing time will be long, resulting in poor practicality.If it exceeds 4, the foam hardness, which is the object of the present invention, will not be soft.

If the molecular weight per hydroxyl group in (b) is less than 400, the foam becomes a closed cell and the cushigonic properties are lost, and if it exceeds 2,400, the compression set becomes poor and the curing time increases, making it impractical.

The polyoxyethylene chain of (b) is 20% by weight of the total molecular weight
If it exceeds this, the form will collapse.

The weight ratio of (a) and (b) is (a)/(b) = 30/7
0-70/30. Preferably 40/60 to 80/4
It is 0. If (a) is less than 30, a soft urethane foam with the foam hardness that is the object of the present invention cannot be obtained;
If it exceeds 70, the form will collapse.

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 number of carbon atoms in the NGO group) [2,4- and/or 2.
8-) Lylene diisocyanate (TDI), crude TDI
, 2,4- and/or 4,4'-diphenylmethane diisocyanate (MD I ), crude MDI [crude diaminodiphenylmethane (condensation product of formaldehyde and aromatic amines (anilines) or mixtures thereof: diaminodiphenylmethane and Small amount (e.g. 5-20
% by weight) of trifunctional or more functional polyamine): Polyarylpolyisocyanate (PA
P I ) Aliphatic isocyanates with 2 to 18 carbon atoms, such as hexamethylene diisocyanate, lysine diisocyanate, etc. Alicyclic polyisocyanates with 4 to 15 carbon atoms (infuron diisocyanate, dicyclohexyl diisocyanate, etc.) 8 to 15 aromatic aliphatic polyisocyanates [such as quinrylene diisocyanate and modified products of these polyisocyanates (urethane group, carbodiimine group, allophanate group, urea group, biuret group, uretdione group, uretonimine group, incyanurate group, oxazolidone group-containing modified products, etc.): and polyisocyanates other than the above described in Japanese Patent Application No. 199160/1982: and these 2
Examples include mixtures of more than one species. Among these, preferred are 2,4- and 2,6-TDI, and mixtures of these isomers.

As the foam stabilizer, one for soft urethane foam is usually used. For example, L-540 (EF Hon Unicar Co., Ltd.)
, 5H-190, 5RX-294A (Toray Silicon (
Co., Ltd.).

Any known catalyst can be used. In particular, 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; 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 normally used for polyurethane foam can be used, and water alone or a combination of water and methylene chloride can be used, preferably water alone.Also, according to the present invention, the foam can have a soft hardness even without using fluorocarbons. If you need a softer material, you can also use Freon.

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

The amount of blowing agent used is not particularly limited, but in the case of water, the amount used is usually 2 to 8 parts, preferably 3 to 7 parts, per 100 parts of polyol. The number of parts of foam stabilizer used is 100 parts of polyol.
Normally 0. 5 to 5 parts, preferably 1 to 3 parts. The amount of catalyst used is usually 0.0 parts per 100 parts of polyol.
01 to 3 parts, preferably 0.05 to 2 parts. In the case of a tin catalyst, the amount used is usually 0.00 parts per 100 parts of polyol.
01 to 3 parts, preferably 0.05 to 2 parts.

The amount of isocyanate used is usually 70~ as the NGO index.
1201 Preferably it is 80-110.

The production method of the flexible polyurethane foam according to the present invention can be carried out by one of the so-called slab, hot cure, and cold cure methods, and among these, the slab and hot cure methods are preferable, and the hot cure one method is particularly preferable. In one hot cure method, the mold temperature during injection of the stock solution is usually 20 to 50°C, preferably 30 to 45°C.
It is ℃. If the temperature is lower than 20°C, the surface of the molded product will become weak. Moreover, when the temperature exceeds 50°C, molding defects such as cracks occur.

[Examples] Hereinafter, the present invention will be further explained with reference to Examples, but the present invention is not limited thereto.

Examples 1-6, Comparative Examples 1-2 Table 1.2 shows flexible polyurethane foam forming compositions. Using this composition, urethane foam was foamed in a mold according to the foaming recipe shown in Table 1.2, and then the urethane foam was removed from the mold to obtain a flexible polyurethane foam, and its physical properties were measured.

(Foaming conditions) Mold shape: 300 mm x 300 lim x 7
Question 0 Material: Aluminum mold temperature = 35-45°C Raw material stirring time near second Raw material temperature: 25 parts 2°C Cure conditions: 150°C XIO minutes (raw materials used) Poly, ether polyol (a) -1: PO of glycerin Random adduct of /EO, EOO amount 40%, molecular weight 3000° Polyether polyol (a)-2: Random adduct of PO/EO of glycerin, EO content 5 Tsumugi polyether polyol (a)-3: Glycerin PO/EO
Random adduct of polyether polyol (b)-1 with EO content of 7: block adduct of EO-PO of glycerin, 12.7% EOO content, 60 parts of polyol with molecular weight 4000, and PO/EO of glycerin adduct, E
A mixture of 12% OO and 40 parts of a polyol with a molecular weight of 3000.

Polyether polyol (b)-2: E of glycerin
Block adduct of O-PO, EOO content 12.7%, polyol 16.6 parts with molecular weight 4000, and glycerin P
A mixture of an O/EO adduct, a POO adduct of propylene glycol with an EO content of 1, and 16.7 parts of a polyol with a molecular weight of 100O.

Comparative polyether polyol: PO/E of glycerin
O adduct, EOO content 12%, molecular weight 3000.

Table-1 T-80: Made by Nippon Polyurethane Co., Ltd., mixture of 2-4/2-6 tolylene diisonanate 80/20 DAB
CO33LV=)9xf diamine 33% product DMEA
= Dimethylethanolamine Table 2 [Effects of addressee] By using the flexible polyurethane foam forming composition of the present invention, a lower Buddha point such as R-11 can be achieved than the polyether polyol used in conventional flexible polyurethane foams. By using only water as a foaming agent without using halogenated hydrocarbons as a foaming agent, the problem of environmental destruction of the earth can be solved.

Claims (1)

[Claims] 1. In a flexible polyurethane foam-forming composition comprising an organic polyisocyanate, a polyol, a catalyst, a blowing agent, and a foam stabilizer, the polyol (a) has a functional group number of 2;
~4, the molecular weight per hydroxyl group is 800 to 1400,
A polyether polyol in which the polyoxyethylene chain accounts for 30 to 70% by weight of the total molecular weight, and (b) (b-1) the number of functional groups is 3 to 4 and the molecular weight per hydroxyl group is 600 to 1100.
The polyoxyethylene chain accounts for 5 to 20% by weight of the total molecular weight.
and (b-2) a polyether polyol having a functional group number of 3 to
4. A polyether polyol with a molecular weight of 1200 to 2400 per hydroxyl group and a polyoxyethylene chain of 20% by weight or less of the total molecular weight, and/or (b-3) a polyether polyol with a functional group number of 2 to 3 and a molecular weight per hydroxyl group. 200-500,
It consists of a polyether polyol, which is a polyoxypropylene chain, and the weight ratio of (a) and (b) is (a).
/(b) = 30/70 to 70/30. 2, (b) is based on the weight of (b) and (b-1) is 4
0-95%, (b-2) 0-60%, (b-3) 0
2. The composition of claim 1 comprising ˜17%. 3. (b) comprises a polyether polyol having an average number of functional groups of 2 to 4, a molecular weight per hydroxyl group of 200 to 2,400, and a polyoxyethylene chain of 20% by weight or less of the total molecular weight. Composition of. 4. The composition according to claim 1, wherein the polyether polyol (a) has 70% or more random polyoxyalkylene chains of oxyethylene and oxypropylene based on the total molecular weight. 5. Organic polyisocyanate and polyol as a catalyst,
In a method for producing flexible polyurethane foam by reacting in the presence of a blowing agent and a foam stabilizer, the polyol (a) has a functional group number of 2 to 4, a molecular weight per hydroxyl group of 800 to 1400, and a polyoxyethylene chain; is 30 to 70% by weight of the total molecular weight,
(b) (b-1) A polyether polyol with a number of functional groups of 3 to 4, a molecular weight of 600 to 1100 per hydroxyl group, and a polyoxyethylene chain of 5 to 20% by weight of the total molecular weight;
b-2) Number of functional groups: 3 to 4, molecular weight per hydroxyl group: 12
00 to 2400, and polyoxyethylene chains are 20% by weight or less of the total molecular weight; and/or (b-3) polyoxypropylene, having a functional group number of 2 to 3 and a molecular weight per hydroxyl group of 200 to 500. It consists of a combination of (a) and (
The weight ratio of b) is (a)/(b) = 30/70 to 70/3
A method for producing flexible polyurethane foam, characterized in that a polyurethane foam having a proportion of 0 is used.