JP2000063473A - Flexible polyurethane foam and its preparation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a flexible polyurethane foam which is lightweight and excellent in vibration-damping property by employing a mixture of a polyether triol with a polyether diol each having a specific mol.wt., an organic polyisocyanate composition and a plasticizer. SOLUTION: The objective flexible polyurethane foam is formed from an active hydrogen compound, an organic polyisocyanate composition, a blowing agent, a crosslinking agent, a foam stabilizer, a catalyst, a plasticizer and other additives. The active hydrogen compound is a mixture comprising (A) a polyether triol having a hydroxyl equivalent of 700-5,000 and (B) a polyether diol having a hydroxyl equivalent of more than 1,000 and not more than 6,000, the wt. ratio of A/B being 80/20-10/90. As the plasticizer is preferable a phthalate ester, which is employed in an mount of about 5-35 pts.wt. based on 100 pts.wt. of the active hydrogen compound. The vibration transmissibility of the flexible polyurethane foam is -5 dB or less at a frequency of 250-350 Hz and -10 dB or less at a frequency of 400-450 Hz.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a flexible polyurethane foam. More specifically, the present invention relates to a flexible polyurethane foam which uses a plasticizer and is lightweight and has excellent vibration damping properties, and a method for producing the same.

[0002]

2. Description of the Related Art Generally, when polyurethane foam is used as a vibration damping material, the foam alone often does not provide sufficient vibration damping properties, and various studies have been conducted to obtain the vibration damping properties. ing. For example, Japanese Patent Laid-Open No. 1-
Japanese Patent No. 275617 discloses a polyurethane foam containing asphalt, and Japanese Unexamined Patent Publication No. 2-084411 discloses a polyurethane foam using calcium carbonate. However, the polyurethane foam containing asphalt or calcium carbonate has a problem that the molding machine is contaminated and the weight of the polyurethane foam becomes heavy.

Further, JP-A-3-081315 discloses a polyurethane foam using a polyether triol and a polyether diol having a hydroxyl equivalent of 500 or less, and JP-A-5-186561 discloses a hydroxyl equivalent of 30 to 500. Polyurethane foam using the polyhydroxyl compound of JP-A-6-184
Japanese Patent No. 264 discloses a polyurethane foam using a polyhydroxyl compound having a hydroxyl equivalent of 500 or less. However, the hydroxyl equivalent is 500
When the following polyether polyols are used, frequency 1
There is a problem that the vibration transmissibility is deteriorated at 00 to 900 Hz, particularly 250 to 450 Hz.

Further, Japanese Patent Application Laid-Open No. 2-84421 discloses that
Using a low molecular weight polyol having a molecular weight of 300 to 500,
A plasticizer having a freezing point of -20 ° C or lower is used as the polyol 100.
Polyurethane foams using from 5 to 150 parts by weight per part by weight are disclosed. However, when a low molecular weight polyol having a molecular weight of 500 or less is used, the frequency of 100 to 9
There is a problem that the vibration transmissibility is deteriorated at 00 Hz, particularly 250 to 450 Hz. Further, if the plasticizer is used in an amount of more than 35 parts by weight, there is a problem that the curing speed of the foam is deteriorated and the productivity is deteriorated. Therefore, in any of the above-mentioned methods, it was impossible to obtain a polyurethane foam having a sufficient vibration damping property by using the polyurethane foam alone.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a flexible polyurethane foam which is lightweight and has excellent vibration damping performance, and a method for producing the same.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have used a mixture of polyether triol and polyether diol having a specific molecular weight, an organic polyisocyanate composition and a plasticizer. As a result, they have found that the above object can be achieved, and completed the present invention. That is, the present invention is a flexible polyurethane foam obtained by reacting an active hydrogen compound and an organic polyisocyanate composition in the presence of a foaming agent, a crosslinking agent, a foam stabilizer, a catalyst, a plasticizer, and other additives. The active hydrogen compound comprises (a) a polyether triol having a hydroxyl equivalent of 700 or more and 5,000 or less, and (b) a polyether diol having a hydroxyl equivalent of more than 1,000 and 6,000 or less, and (b) / (b) A flexible polyurethane foam and a method for producing the same, which comprises using a mixture having a mixing weight ratio of 80/20 to 10/90 of 5 to 35 parts by weight of a phthalate ester as a plasticizer with respect to 100 parts by weight of an active hydrogen compound. And the vibration transmissibility of the flexible polyurethane foam at a frequency of 250 to 350 Hz is -5 dB or less, and 400 to 450
A flexible polyurethane foam having a vibration transmissibility at -10 dB or less at Hz and a method for producing the same.

That is, the present invention provides the following (1) to (6). (1) A flexible polyurethane foam comprising an active hydrogen compound, an organic polyisocyanate composition, a foaming agent, a crosslinking agent, a foam stabilizer, a catalyst, a plasticizer and other additives,
The active hydrogen compound (a) has a hydroxyl equivalent of 700.
A polyether triol of 5,000 or more,
(B) A polyether diol having a hydroxyl equivalent of more than 1000 and not more than 6000, and (b) /
A flexible polyurethane foam characterized by being a mixture having a mixing weight ratio of (b) of 80/20 to 10/90.

(2) The flexible polyurethane foam according to (1), wherein the plasticizer is a phthalic acid ester and is used in an amount of 5 to 35 parts by weight based on 100 parts by weight of the active hydrogen compound.

(3) The flexible polyurethane foam according to (1) or (2), wherein the vibration transmissibility of the flexible polyurethane foam at a frequency of 250 to 350 Hz is-.
A flexible polyurethane foam which is 5 dB or less and has a vibration transmissibility of -10 dB or less at 400 to 450 Hz.

(4) Production of a flexible polyurethane foam obtained by reacting an active hydrogen compound and an organic polyisocyanate composition in the presence of a foaming agent, a crosslinking agent, a foam stabilizer, a catalyst, a plasticizer and other additives. A method wherein the active hydrogen compound has a hydroxyl equivalent (a) of 700 or more 50
And (b) a hydroxyl equivalent of more than 1000 and not more than 6000, and having a mixture weight ratio (a) / (b) of 80/20 to 10/90. A method for producing a flexible polyurethane foam, characterized by being present.

(5) The method for producing a flexible polyurethane foam according to (4), wherein the plasticizer is a phthalic acid ester and is used in an amount of 5 to 35 parts by weight based on 100 parts by weight of the active hydrogen compound.

(6) A flexible polyurethane foam obtained by the method according to (4) or (5), wherein the flexible polyurethane foam has a vibration transmissibility of -5 dB or less at a frequency of 250 to 350 Hz, and 400 to 4
A method for producing a flexible polyurethane foam, characterized in that the vibration transmissibility at 50 Hz is -10 dB or less.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below. The active hydrogen compound used in the present invention is
(A) A mixture of a polyether triol having a hydroxyl equivalent of 700 or more and 5000 or less and (b) a polyether diol having a hydroxyl equivalent of more than 1000 and 6000 or less is preferable, and the polyether triol of (a) The mixing ratio of the polyether diol of (b) is 80 as the mixing weight ratio of (a) / (b).
It is more preferably / 20 to 10/90. (I)
When the mixing weight ratio of is larger than 80, the foam shrinks so much that molding failure tends to occur. If the mixing weight ratio of (a) is less than 10, the foam may collapse due to cell collapse, or the foam may have a slow curing rate and the productivity tends to decrease.

Here, the hydroxyl equivalent of (a) is 70.
The polyether triol of 0 or more and 5,000 or less is one in which one or more kinds of alkylene oxides are added to an initiator having 3 functional groups by a conventional method so that the hydroxyl equivalent becomes 700 or more. .
Moreover, the hydroxyl equivalent of (b) exceeds 1000 and exceeds 600.
The polyether diol having a value of 0 or less is one in which one or more kinds of alkylene oxides are added to an initiator having a functional group of 2 by a conventional method so that the hydroxyl equivalent is 1000 or more. When the hydroxyl equivalent of the polyether triol of (a) is less than 700, the vibration transmissibility tends to be deteriorated, and 5
If it exceeds 000, there is a problem that the viscosity of the polyether triol tends to increase. When the hydroxyl equivalent of the polyether diol (b) is less than 1000, the vibration transmissibility tends to be poor, and
If it is larger, there is a problem that the viscosity of the polyether diol tends to increase. In addition, generally, the hydroxyl equivalent is a value obtained by dividing the molecular weight of the polyether polyol by the number of functional groups of the initiator.

In the above-mentioned (a) polyether triol, examples of the initiator having 3 functional groups include glycerin, triethylene glycol, trimethylolpropane and the like. In the polyether diol of (b), examples of the initiator having 2 functional groups include, for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol and the like. Examples of the alkylene oxide added to the above initiator include propylene oxide, ethylene oxide, butylene oxide, styrene oxide and the like. Further, the active hydrogen compound of the present invention is obtained by polymerizing (radical) an ethylenically unsaturated compound such as acrylonitrile or styrene in the presence of the above polyethertriol (a) and / or polyetherdiol (b) to give polyacrylonitrile, A polymer-dispersed polyol obtained by dispersing polystyrene, a copolymer thereof, or the like in the above polyether triol (a) and / or polyether diol (b), commonly known as polymer polyol (trade name)
Can also be preferably used.

The organic polyisocyanate composition used in the present invention is a mixture of diphenylmethane diisocyanate and tolylene diisocyanate, and the composition ratio and the like are not particularly limited, and any ratio can be used. As the above mixture, specifically,
For example, 4,4′-diphenylmethane diisocyanate (hereinafter diphenylmethane diisocyanate is referred to as MDI), 2,4′-MDI, 2,2′-MDI, a trinuclear or higher methylene-bridged polyphenyl polyisocyanate,
It is a mixture of 2,4- and / or 2,6-tolylene diisocyanate (hereinafter, tolylene diisocyanate is referred to as TDI). Further, the TDI used in the present invention does not inhibit the effect of the present invention due to its isomer ratio, but in particular, its isomer ratio is 2,4-TDI / 2,6-T.
Those contained within the range of DI = 100/0 to 65/35 (weight ratio) are preferable. The organic polyisocyanate composition of the present invention may be urethane-modified with a polyoxyalkylene polyol, and may include, for example, a carbodiimide-modified product.

As the foaming agent in the present invention, water is used as the sole foaming agent. The amount of water used is preferably 2.0 to 6.5 parts by weight, more preferably 2.5 to 6.0 parts by weight, per 100 parts by weight of the active hydrogen compound. When the amount of water is less than 2.0 parts by weight, the expansion ratio of the flexible polyurethane foam tends to decrease and the density tends to increase. When the amount of water is more than 6.0 parts by weight, the curing reaction of the flexible polyurethane foam deteriorates and the productivity is increased. And the moldability tend to deteriorate.

The structure of the crosslinking agent used in the present invention is not particularly limited, but polyhydric alcohols such as ethylene glycol and propylene glycol, or those obtained by adding a small amount of alkylene oxide thereto, such as diethanolamine and triethanolamine. The amines or those obtained by adding a small amount of alkylene oxide thereto can be used alone or as a mixture. The amount used is 0.1 to 10 parts by weight per 100 parts by weight of the active hydrogen compound.
More preferably, it is 0.5 to 5 parts by weight. When the amount used is less than 0.1 part by weight, the curability of the surface of the foam tends to deteriorate, and when it is more than 10 parts by weight, the foaming ratio of the foam tends to decrease and the density tends to be low. It tends to be high, which is not preferable.

The foam stabilizer used in the present invention is not particularly limited, but specific examples thereof include known organosilicon surfactants (polysiloxane-polyoxyalkylene copolymer). For example, SRX-253, SRX-274C, SF-29 manufactured by Toray Dow Corning Co., Ltd.
61, SF-2962, SF-2969, Nippon Unicar L-5309, L-5307, L-5305, L
-3600 etc. (both are trade names) can be used. The amount of the hydrogen peroxide used is 100 parts by weight per 100 parts by weight of the active hydrogen compound.
It is 1 to 5 parts by weight, preferably 0.1 to 3 parts by weight.

The catalyst used in the present invention may be a known catalyst and is not particularly limited, but specifically,
For example, there are amine-based catalysts such as triethylenediamine, N-methylmorpholine and N-ethylmorpholine, and organometallic catalysts such as tin octylate, tin oleate and dibutyltin dilaurate. These catalysts can be used alone or in combination. The amount used is 0.001 to 5 parts by weight, preferably 0.1 to 5 parts by weight, per 100 parts by weight of the active hydrogen compound.

The plasticizer used in the present invention is preferably a phthalate ester, and specific examples thereof include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, dioctyl phthalate and phthalate. Examples thereof include esters of phthalic acid and alcohol such as diisononyl acid and diisodecyl phthalate. These plasticizers can be used alone or in combination. The amount used is 5 to 35 per 100 parts by weight of the active hydrogen compound.
Parts by weight, preferably 10 to 20 parts by weight. If the amount of the plasticizer used is less than 5 parts by weight, the vibration transmissibility tends to be poor, and if it is more than 35 parts by weight, the curability of the foam tends to be lowered, Not preferable.

Other additives include flame retardants, colorants,
Antiaging agents, antioxidants and the like can be used as necessary.

The method for producing the flexible polyurethane foam of the present invention is not particularly limited, but usually an active hydrogen compound, a foaming agent, a cross-linking agent, a foam stabilizer, a catalyst, a plasticizer, and other additives. After mixing in advance to obtain a resin premix, this is mixed with an organic polyisocyanate at a predetermined ratio, and the mixture is injected into a mold to cause reaction and foaming. At that time, the NCO index (equivalent ratio of isocyanate groups in the organic polyisocyanate to active hydrogen in the resin premix = NCO / H), which is the reaction ratio between the resin premix and the organic polyisocyanate, is 0.6.
The range of to 1.0 is preferable. More preferably 0.7-
It is in the range of 0.9. If the NCO index is smaller than 0.6, the density of the flexible polyurethane foam tends to be high, and the cure property of the foam surface tends to be deteriorated. When the NCO index is larger than 1.0, the vibration transmissibility tends to be deteriorated. After injecting into the mold, it is left to stand in an atmosphere of room temperature to 100 ° C. for 3 to 30 minutes for reaction curing, and then the flexible polyurethane foam is taken out from the mold.

As a method for evaluating the vibration damping performance of the flexible polyurethane foam or the like obtained by the present invention, there is, for example, a sensory test in which the foam is actually used. In the present invention, the vibration transmissibility of the foam is measured. , To evaluate the vibration damping performance of polyurethane foam. According to this method, it is possible to evaluate the vibration damping performance by digitizing it, which was not possible in the past, and it was possible to further improve the evaluation technique.

The vibration transmissibility of the flexible polyurethane foam of the present invention is measured and evaluated by the following method. Specifically, a foam with a thickness of 20 mm and a vinyl chloride resin mat with a thickness of 2 mm are placed in this order on the iron plate of the vibration source, and vibration is applied at a frequency of 10 to 1000 Hz to accelerate the acceleration between the iron plate and the vinyl chloride mat. Find the amount of displacement. The lower the vibration transmissibility, the better the damping performance. In the present invention, as the evaluation of the vibration transmissibility of the flexible polyurethane foam, particularly the frequency of 250 Hz, 30
Numerical values of 0 Hz, 350 Hz, 400 Hz and 450 Hz were used.

The flexible polyurethane foam of the present invention has a vibration transmissibility of -5 dB or less at a frequency of 250 to 350 Hz and is 400 to 450 Hz as a result of measurement and evaluation by the above-described vibration transmissibility measuring method.
A flexible polyurethane foam having a vibration transmissibility of -10 dB or less is more preferable as a flexible polyurethane foam having significantly superior vibration damping performance as compared with a conventional flexible polyurethane foam.

[0027]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

(1) Preparation of resin premix Distilled water or ion-exchanged water was added to 100 parts by weight of a mixture of polyethertriol and polyetherdiol.
0 parts by weight, foam stabilizer A (manufactured by Nippon Unicar Co., Ltd., trade name: L-
5309) 1.0 part by weight, amine catalyst A (manufactured by Active Material Chemical Co., trade name: Minico L-1020) 0.6 part by weight, amine catalyst B (manufactured by Active Material Chemical Co., trade name: TM
0.1 parts by weight of DA) and 0.3 parts by weight of amine catalyst C (manufactured by Sankyo Air Products Co., Ltd., trade name: Dabco X-DM), and mixed by stirring to obtain a resin premix.

(2) Preparation of organic polyisocyanate composition 50 parts by weight of dissolved 4,4'-MDI and crude MDI
(Mitsui Toatsu Chemical Co., Ltd., trade name: Cosmonate M-20
0) 75 parts by weight of polymethylene polyphenyl polyisocyanate, which is a mixture of 50 parts by weight, and 25 parts by weight of TDI (trade name: T-80, manufactured by Mitsui Toatsu Chemicals, Inc.) were mixed to prepare an organic polyisocyanate composition. .

(3) Measurement of foaming of mold and vibration transmissibility Table 1 shows resin premix and organic polyisocyanate.
500 × 500 × 20 m adjusted to 50 ± 2 ° C. by vigorously stirring and mixing for 4 seconds at the NCO index described in 2.
Add to m mold. The foaming pressure in the mold was released 2 minutes after the mixed reaction solution was charged, the polyurethane foam was taken out of the mold 5 minutes later, and allowed to stand in a room temperature-controlled at 25 ° C. for 24 hours, and then the vibration transmissibility was measured. .

Tables 1 and 2 show the results of Examples 1 to 6 and Comparative Examples 1 to 4 of mold foaming performed by changing the composition of the polyol composition.

[0032]

[Table 1]

[0033] (Note) Explanation of symbols   ・ Plasticizer A: dimethyl phthalate   -Polyether triol A: hydroxyl equivalent = 2330                               EO content = 14% by weight   -Polyether triol B: hydroxyl equivalent = 1700                               EO content = 14% by weight   -Polyether triol C: hydroxyl equivalent = 2000                               EO content = 15% by weight   -Polyether triol D: hydroxyl equivalent = 330                               EO content = 0% by weight   -Polyether diol E: hydroxyl equivalent = 1500                               EO content = 20% by weight   -Comparative Example 1: Evaluation is impossible because the foam shrinks severely and cannot be molded.   -Comparative example 2: The curability of the foam deteriorated, and a good molded product could not be obtained.               Therefore, it cannot be evaluated.

[0034]

[Table 2]

(Note) Explanation of symbols ・ Plasticizer A: dimethyl phthalate ・ Plasticizer B: diethyl phthalate ・ Plasticizer C: dibutyl phthalate ・ Plasticizer D: Dioctyl phthalate ・ Plasticizer E: diisodecyl phthalate

[0036]

EFFECTS OF THE INVENTION According to the present invention, as a flexible polyurethane foam and a method for producing the same, (a) a polyether triol having a hydroxyl equivalent of 700 or more and 5000 or less, and (b) a hydroxyl equivalent of more than 1000 and 6000.
Consisting of the following polyether diols, (a) /
By using a polyol composition, an organic polyisocyanate composition, and a plasticizer having a mixing weight ratio of (b) of 80/20 to 10/90, the vibration transmissibility at a frequency of 250 to 350 Hz is −5 dB or less, 400 to 450Hz
It has become possible to provide a flexible polyurethane foam which has excellent vibration damping performance of -10 dB or less and has a light weight, and a manufacturing method thereof. Further, the flexible polyurethane foam can be used for a vibration damping material alone or in combination with other foams.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08G 101: 00) C08L 75:04 (72) Inventor Kunio Sasaoka 1190 Kasama-cho, Sakae-ku, Yokohama, Kanagawa Mitsui Chemicals In-house F-term (reference) 4F074 AA80 AB00 AB01 AD11 AG02 BA34 BB01 BB08 BB10 BC01 CA21 CA23 CC04Y CC32Y DA17 DA24 DA40 4J002 CK031 CP182 DE026 EH148 EN037 EU237 EZ047 FD028 FD157 CB307 FD326 4J05 CA13 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CA04 CD01 CD04 DA01 DB04 DB05 DB07 DG02 DG03 DG04 DG05 DG14 DG16 DQ05 DQ16 DQ18 HA01 HA02 HA06 HA07 HA14 HB06 HB07 HC12 HC61 HC64 HC67 HC71 KA01 KB02 KC17 KD02 KD12 KE02 MA12 NA03 NA08 QA02 QB15 RA15 Q19

Claims (6)

[Claims] 1. A flexible polyurethane foam comprising an active hydrogen compound, an organic polyisocyanate composition, a foaming agent, a cross-linking agent, a foam stabilizer, a catalyst, a plasticizer and other additives, the active hydrogen compound comprising: A) Polyethertriol having a hydroxyl equivalent of 700 or more and 5,000 or less, and (b) a hydroxyl equivalent of more than 1000 and 6000
Consisting of the following polyether diol, (a) /
A flexible polyurethane foam characterized by being a mixture having a mixing weight ratio of (b) of 80/20 to 10/90. 2. The flexible polyurethane foam according to claim 1, wherein the plasticizer is a phthalic acid ester and is used in an amount of 5 to 35 parts by weight based on 100 parts by weight of the active hydrogen compound. 3. The flexible polyurethane foam according to claim 1, wherein the flexible polyurethane foam has a vibration transmissibility of -5 dB or less at a frequency of 250 to 350 Hz and a vibration transmissibility of -10 dB at 400 to 450 Hz. A flexible polyurethane foam characterized in that: 4. A foaming agent, a cross-linking agent, a foam stabilizer, a catalyst, a plasticizer, an active hydrogen compound and an organic polyisocyanate composition,
A method for producing a flexible polyurethane foam obtained by reacting in the presence of other additives, wherein the active hydrogen compound is (a) a polyether triol having a hydroxyl equivalent of 700 or more and 5,000 or less, and (b) a hydroxyl equivalent. Is greater than 1000 and is less than or equal to 6000, and the mixing weight ratio of (a) / (b) is 8
A method for producing a flexible polyurethane foam, which is a mixture of 0/20 to 10/90. 5. The method for producing a flexible polyurethane foam according to claim 4, wherein the plasticizer is a phthalic acid ester and is used in an amount of 5 to 35 parts by weight based on 100 parts by weight of the active hydrogen compound. 6. A flexible polyurethane foam obtained by the method according to claim 4 or 5, wherein the flexible polyurethane foam has a vibration transmissibility of -5 dB or less at a frequency of 250 to 350 Hz and 400 to 450 Hz.
And a vibration transmissibility of 10 dB or less.