JPH0381315A - Production of polyurethane foam - Google Patents

Abstract

PURPOSE:To produce a polyurethane foam exhibiting an excellent soundproof effect in a medium-frequency range, having a low density and good curing properties, and enabling mold foaming at a high productivity by reacting an org. polyisocyanate with a specific high-molecular polyol. CONSTITUTION:An org. polyisocyanate, esp. pref. TDI or MDI, is reacted with at least 20wt.% high-molecular polyol comprising at least partially a polyoxyethylene(an equivalent of 1,000 or higher)-terminated polyol (a) having a functionality of at least 5 [the polyol (a) being composed of a polyol having an internally random polyoxyalkylene chain and/or a block polyoxyalkylene polyol] and/or the component (a) modified with an ethylenically unsatd. monomer in an NCO/OH equivalent ratio of 0.4-0.9 in the presence of a blowing agent, a catalyst, and other additives to produce a polyurethane foam having an apparent density of 200kg/m<3> or lower.

Description

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

More specifically, the present invention relates to a method for producing soundproof molded polyurethane foam that is foamed in a mold.

[Conventional technology] Conventionally, polyol and organic polyisocyanate were used as a blowing agent,
When producing flexible polyurethane foams by the one-shot method in the presence of catalysts, foam stabilizers and other additives, urethane prepolymers with viscous terminal inert groups (isocyanate groups of the urethane prepolymers are replaced with methanol, etc.) Adding alcohol, monohydric carboxylic acid, or deactivated with secondary amine) to polyol, it can be used for soundproofing,
A method of manufacturing a polyurethane foam having vibration damping properties is known (for example, Japanese Patent Laid-Open No. 56-205115).

[Problems to be Solved by the Invention] Urethane foam containing the above-mentioned urethane prepolymer with terminal inert groups has a high viscosity as a raw material, so when poured into a mold, the flowability of the raw material inside the mold is poor. It has disadvantages of poor foam formation and long demolding time, resulting in poor productivity.

Another disadvantage is that the foam density tends to be high, and when the density is lowered, the soundproofing performance decreases.

[Means for Solving the Problems] The present inventors conducted studies to find a method for producing polyurethane foam that has excellent soundproofing effects in the medium frequency range, has low density, has good curing properties, and can be molded with high productivity. As a result, we have arrived at the present invention.

That is, the present invention provides a method for producing polyurethane foam by reacting an organic polyisocyanate and a polymeric polyol in the presence of a blowing agent, a catalyst, and other additives. A terminal polyoxyethylene chain-containing polyol (A) having a group number of 5 or more and an equivalent weight of 1000 or more [However, (A) is a polyol (A1) having an internal random polyoxyalkylene chain.
), and/or block polyoxyalkylene polyol (A2)] and/or modified with an ethylenically unsaturated monomer (A) is used in an amount of 20% by weight or more, and (2) the equivalent amount of NCO/OH is used. The ratio is 0.4 to 0.9 (
3) A method for producing a polyurethane foam characterized by a foam density of 200 kg/m' or less, and a method for producing a polyurethane foam by reacting an organic polyisocyanate and a polymeric polyol in the presence of a blowing agent, a catalyst, and other additives. (1) A terminal polyoxyethylene chain-containing polyol (A) having a functional group number of 5 or more and an equivalent weight of 1000 or more as at least a part of the polymer polyol [However, (A) is an internal random polyoxyalkylene chain. A polyol (A1
), and/or block polyoxyalkylene polyol (A2) modified with a co- and/or ethylenically unsaturated monomer (A) of 20% by weight or more and based on the weight of the total polyol, ○H equivalent 2000 or less monool, or 10 to 70% of diol or triol having OH equivalent of 500 or less, and (2) N
This is a method for producing a polyurethane foam characterized by having a CO/OH equivalent ratio of 0.4 to 0.9 (3) and a foam density of 200 kg/m' or less.

In the present invention, the polyol (A1) used as at least part or all of the polymer polyol is a compound having at least 5 (preferably 6 to 12) active hydrogen atoms (e.g., polyhydric alcohol, polyhydric Examples include compounds having a structure in which ethylene oxide and other alkylene oxides are added to (phenol, amines) so as to form terminal oxyethylene chains and internal random polyoxyalkylene chains, and mixtures thereof.

Examples of the polyhydric alcohol include sugar alcohols such as pentitol such as adonitol, arabitol, and xylitol; hexitol such as sorbitol, mannitol, iditol, talitol, and dulcitol; sugars such as monosaccharides such as glucose, mannose, fructose, and sorbose, and sucrose; Oligosaccharides such as trehalose, lactose, raffinose: Glycosides Glycosides of polyols (e.g. glycols such as ethylene glycol, propylene glycol, alkane polyols such as glycerin, trimethylolpropane, hexanetriol, pentaerythritol): Poly(alkane polyols) e.g. Glycerin, polyglycerin such as tetraglycerin, cichentaerythritol,
Polypentaerythritols such as tripentaerythritol; and cycloalkane polyols such as tetrakis(hydroxymethyl)cyclohexanol. The above polyhydric phenols include novolac,
Examples include polyphenols described in US Pat. No. 3,265,641; and examples of amines include polyalkylene polyamines such as diethylenetriamine and triethylenetetramine. Two or more of these active hydrogen atom-containing compounds may be used in combination. In addition, in a mixture of one or more of these compounds and a compound having 2 to 4 active hydrogen atoms (for example, those mentioned as raw materials for the polyether polyol in (B) below), the average number of functional groups (active hydrogen atoms number) is 5 or more (preferably 6 to 12)
You can also use. Preferred among these are polyhydric alcohols, particularly preferred are sorbitol and sucrose.

Propylene oxide (abbreviated as PO) is usually used as another alkylene oxide (abbreviated as AO hereafter) to be added together with ethylene oxide (abbreviated as EO hereafter) to the above active hydrogen atom-containing compound. oxide, styrene oxide, etc.)
It is also possible to use a small amount (for example, 5% or less) in combination.

The above polyol (A) used in the present invention.

), a mixture of EO and PO is added to a compound (base compound) or its AO adduct (base polyether) having at least 5 active hydrogen atoms as described above, and then other AO is added as necessary. A polyol obtained by adding EO to the terminal can be used.Such a polyol has the following general formula %Formula % (1) In the general formula (1), R represents at least two active hydrogen atoms. Residues removed: n is an integer of 5 or more: E'0'/P''o2 is a random polyoxyalkylene group consisting of an oxyethylene group and an oxypropylene group, E'O' is an oxyethylene group: A, O and A20 is an oxyalkylene group dia,
bXc, d are 0 or positive integers, and n a's, n su's, rt's c's, and n's d's may be the same or different, and the sum of n a's, n a's The sum of C may be 0.

In the present invention, the above polyol (A,) and block polyoxyalkylene polyol (A2) can also be used in combination. (A2) includes at least 5
EO and other AOs are added to a compound having active hydrogen atoms in the order (I) AO-EO (tipped), (■) AO-EO-AO-EO (7). Noku Balanced), (III) EO-A
Examples include those added in the order O-EO.

The number (average) of functional groups in the polyol (A) [(AI) and/or (A2)] used in the present invention is 5 or more, preferably 6 to 12. If the number of functional groups is less than 5, a mold form with excellent soundproofing effects and excellent curing properties, which are the objectives of the present invention, cannot be obtained.

The equivalent weight (molecular weight per OH) of polyol (A) is usually 1
000 or more, preferably 1100 to 3200, particularly preferably 1200 to 2500. If the equivalent weight is lower than 1,000, the foam becomes hard and the physical properties such as soundproofing performance and elongation of the obtained polyurethane deteriorate.

If the equivalent weight exceeds 3,200, the viscosity becomes high and the liquid flow within the mold becomes poor, and the reactivity decreases and the cure property of the mold form becomes poor, making it difficult to use.

Terminal polyoxyethylene chain content (hereinafter referred to as terminal EO) of (A)
The amount (abbreviated as "amount") is usually 5% (weight %, the same applies hereinafter) or more, preferably 7 to 30%, and more preferably 10 to 15%. If the amount of terminal EO is less than 5%, the reactivity will be low and the curing properties will be poor, making it impossible to form a satisfactory mold bottom. If the amount of terminal EO exceeds 30%, the curing properties will improve, but the foam will tend to shrink due to strong closed cells, and the viscosity will increase and become cloudy at a temperature slightly lower than room temperature, resulting in poor workability and physical properties. In other words, the foam becomes more likely to absorb water.

In addition, even if the amount of terminal EO is less than 5%, the amount of terminal EO is 5%.
% or more, or those with a terminal EO content of more than 20% are combined with those with a terminal EO content of 20% or less, and used in combination so that the overall (average) terminal EO content falls within the above range. The same applies to the equivalent weight and the number of functional groups.

The total polyoxyethylene chain content (hereinafter abbreviated as total EO amount) of (A) is usually 5% or more, preferably 7 to 30%, and more preferably 10 to 15%.

In addition, in (AI), random polyoxyalkylene chain -(E゛0°
The weight ratio of oxyethylene groups and oxypropylene groups in /P゛0'')b- is usually 9G:10-30 near 0,
Preferably 80:20 to 40:60, more preferably 7
The time is from 5:25 to 45:55. When the weight ratio of oxyethylene groups exceeds 90, the crystallinity improves, so the obtained polyether polyol can be used in cold conditions (at a temperature slightly lower than room temperature).
Causes clouding. Furthermore, the reactivity becomes too high, resulting in a closed cell foam, which shrinks and makes it impossible to obtain a good foam. On the other hand, if the weight ratio of oxyethylene groups is 2
If it is less than 0, the internal activation force will be weakened, the curing property will be lowered, and it will be difficult to remove the mold form quickly.

The content of said random polyoxyalkylene chains in the polyether polyol is at least 5% of the total molecular weight, preferably from 5 to 25%. When the content of random polyoxyalkylene chains is less than 5% of the total molecular weight, the internal activation force is small and the curing property is low, so that the surface of the mold form tends to become loose skin. When it exceeds 25%, the water absorption of the mold foam is large and the reactivity is too high, which tends to cause defects in the surface condition of the mold foam. The proportion of the oxyethylene group present in the random polyoxyalkylene chain in the total molecule is usually 1.5 to 22.5%, preferably 2.0 to 20%. The position of the random polyoxyalkylene chain in the polyol (A1) (E O-
It is preferable that the addition position of the P 2 O mixture is at the end of 60% of the total molecular weight. That is, the ratio of the total molecular weight of the base polyether (R[-(AIO), Hl.) before random addition to the molecular weight of the polyether polyol is 6.
It is preferable to set it to 0% or more. Alkylene oxide (AI) used to form the above base polyether
PO is normally used as O), but other AO
(Ethylene oxide, butylene oxide, styrene oxide, etc.) may also be used in small amounts (for example, 5% or less).

The base polyether has an OH value of 23 to 83 (especially 25 to 83).
67) is preferred. The random polyoxyalkylene chain and the terminal polyoxyethylene chain may be bonded directly or via a polyoxyalkylene chain -(A20)c-. In the latter case, the alkylene oxide (A20) used to form the intervening polyoxyalkylene chain
Although propylene oxide is usually used as the
A small amount (for example, 5% or less) of alkylene oxide having 4 or more carbon atoms such as styrene oxide can also be used in combination.

In the present invention, the polyol (A) [(AI) and/or (A2)] may be a so-called polymer polyol modified with an ethylenically unsaturated monomer. Monomers used in the production of polymer polyols include the following.

(I) Acrylic acid, methacrylic acid and derivatives thereof: acrylonitrile, methacrylonitrile, acrylic acid,
Methacrylic acid and its salts, methyl acrylate, methyl methacrylate, dimethylaminoethyl methacrylate, acrylamide, methacrylic acid amide, etc.

(n) Aromatic vinyl monomer: styrene, α-methylstyrene, etc.

(II) Olefinic hydrocarbon monomer: ethylene, propylene, butadiene, imbutylene, isopropylene,
1.4-pentagene, etc.

(IV) Vinyl ester monomer: vinyl acetate, etc.

(V) Vinyl halide monomer: vinyl chloride, vinylidene chloride, etc.

(VI) l-ninyl ether II mer: vinyl methyl ether, etc.

Preferred among these are acrylonitrile, methyl methacrylate, styrene and butadiene, and particularly preferred are acrylonitrile and a combination of acrylonitrile and styrene (styrene:acrylonitrile weight ratio 10:90 to 60:40).

The polyol (A) may be one partially modified with a monomer [for example, modified (A)].

) and native (A1), modified (A1) and native (A2), or native (A1) and modified (A
It may be used in combination with 2) or may be completely modified.

Further, the polyol (A) may be modified with a monomer by mixing another polymer polyol (B) with a monool (C) or diol CD) or triol (E) described below, if necessary. In this case, the amount of unmodified (A) in the total amount of polyol is usually 20% or more, and the amount of monool, diol, triol is usually 50% or less.

The proportion of monomers used for modification can vary over a wide range, but is usually 2 to 100 parts by weight of the polyol [ethylenic unsaturated monomer or polymer per 1100 parts by weight of the unmodified (A) and optionally other polyol]. It is 70 parts by weight, preferably 5 to 40 parts by weight.

Modification of a polyol with an ethylenically unsaturated monomer (manufacture of a polymer polyol) can be carried out by a conventional method. For example, modification of an ethylenically unsaturated monomer in a polyol in the presence of a polymerization catalyst (radical generator, etc.) Lower polymerization method (U.S. Pat. No. 3,383,351, Japanese Patent Publication No. 39-2478)
No. 7, Special Publication No. 47-47999, Japanese Patent Publication No. 158-1973
94) and a method in which a polymer obtained by prepolymerizing the above monomers and a polyol are graft-polymerized in the presence of a radical generator (Japanese Patent Publication No. 47-47597). The former method is preferred. As the polymerization catalyst (radical generator) used in the polymerization reaction, azo compounds, peroxides, persulfates, perborates, etc. can be used, but azo compounds are practically preferred.The amount used is also particularly limited. For example, usually 0.1 to 20 parts by weight per 100 parts by weight of ethylenically unsaturated monomer (or polymer),
Preferably it is 0.1 to 15 parts by weight. The above polymerization can also be carried out in the presence of a solvent such as toluene, xylene and the like. The reaction temperature is usually 50 to 170°C, preferably 90 to 150°C.

In implementing the polyurethane manufacturing method of the present invention,
It can be carried out by reacting the polyol (A) alone or in combination with another polymeric polyol (B) and/or monool (C) or diol (D) or triol (E) with an organic polyisocyanate. .

As other polymeric polyols (B) that may be used in combination, polyether polyols, polyester polyols, and polymer polyols other than (A) can be used.

As polyether polyols other than (A), 2 to 4
Compounds having active hydrogen atoms (low-functional polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol,
Dihydric alcohols such as neopentyl glycol, l,6-hexanediol, trihydric alcohols such as glycerin, trimethylolpropane, hexanetriol, triethanolamine, tetrahydric alcohols such as pentaerythritol and methyl glucoside; polyhydric phenols such as hydroquinone , bisphenol A: A of amines such as ethylenediamine, aminoethylpiperazine, etc.
Low-functionality polyether polyols such as O adducts (such as EO and/or PO), polytetramethylene ether glycol; <10%> (PO adducts, PO/E
O random adducts, P O/E O block adducts having polyoxyethylene chains only internally), and those with an equivalent weight of less than 1000. As the polyester polyol, the above-mentioned low-functional polyhydric alcohols (ethylene glycol, diethylene glycol, etc.) are used.
polycarboxylic acid (for example, adipic acid, maleic acid, phthalic acid, etc.) or its anhydride to the above-mentioned low-functionality polyether polyol. Objects and AOs (E○, PO, etc.)
or by reacting (condensing) lactones (
Examples include those obtained by ring-opening polymerization of ε-caprolactone, etc.). Polymer polyols include polyols obtained by polymerizing these polyols (polyether polyols and/or polyester polyols, etc.) and ethylenically unsaturated monomers (acrylonitrile, styrene, etc.) (for example, JP-A-54-108).
No. 99, as described in JP-A-54-122396)
can be mentioned. Among (B), preferred are polyether polyols [especially low-functional polyether polyols having terminal polyoxyethylene chains (diols and/or triols, terminal EO content 10 to 30%)]
and its polymer polyol.

The amount of (A) in the total amount of the polymer polyol [(A) and optionally (B)] is usually 20% or more, preferably 30% or more. If (A) is less than 20%, a foam with good curing properties cannot be obtained. In addition, when using a polymer polyol modified with a monomer as at least a part of the polymer polyol [(A) and (B) if necessary, the unmodified polymer polyol portion (polymer polyol) The proportion of the unmodified portion (A) in the total amount (excluding portions) is usually 10% or more, preferably 20% or more, and more preferably 30% or more.

The amount of terminal EO in the entire polymer polyol is usually 5% or more, preferably 7 to 30%, and more preferably 10 to 15%. In addition, the equivalent weight average of the entire polymer polyol is usually 11
00-3200, preferably 1200-2500.

Monools (C) include monohydric alcohols having 1 to 18 or more carbon atoms (for example, fatty acids such as methanol, ethanol, n- and iso-7' lobanol, butanol, 2-ethylhexyl alcohol, cyclohexanol, benzyl alcohol, etc.); monohydric phenols (e.g. phenols,
alkylphenols such as nonylphenol); and oxyalkylene derivatives (alkylene oxide adducts) of monofunctional active hydrogen atom-containing compounds. Examples of monofunctional active hydrogen atom-containing compounds include monohydric alcohols, monohydric phenols, and other compounds having one active hydrogen atom in the molecule [secondary amines (e.g., monomethylpropylamine, di-n -butylamine,
diCl-C2゜alkylamines such as monomethylstearylamine, heterocyclic amines such as morpholine), monovalent C1~
C2° mercaptan, C1-C2o monocarboxylic acid, etc.]. The AO usually has 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms, such as EOXPo, 1,2.
2.3-1.3- and 1.4-butylene oxide, etc., and combinations of two or more of these (random and/or
or block addition), and the preferred one is PO
lEO and their combinations. Oxyalkylene derivatives can be obtained by addition polymerizing alkylene oxide by a conventional method. The number of moles of alkylene oxide added is usually 1 to 100 moles, preferably 4 to 25 moles, per mole of the monofunctional active hydrogen atom-containing compound.

Among monofunctional active hydrogen atom-containing compounds, oxyalkylene derivatives are preferred, especially those having a molecular weight of 100 to 3,000.
belongs to. The OH equivalent of monool is 2000 or less,
Preferably it is 1500 or less.

Examples of the diol (D) include ethylene glycol, diethylene glycol, dipropylene glycol, butanediol, neopentyl glycol, hexanediol, polyethylene glycol and polypropylene glycol with a molecular weight of 200 to 400, low molecular weight diols having a cyclic group (for example, Japanese Patent Publication No. 45 -Those described in Publication No. 1474; propylene oxide adduct of bisphenol A, etc.)
, tertiary or quaternary nitrogen atom-containing low-molecular diols (for example, those described in Japanese Patent Publication No. 130699/1983; alkyl dialkanolamines and quaternized products thereof), thiodiethylene glycol, and the like. Among these, preferably polypropylene glycol has an OH equivalent of 500 or less, more preferably 300 or less.

Triols (E) include glycerin, trimethylolpropane, triethanolamine, tris or tetrakis(hydroxypropyl)ethylenediamine, diethyldiaminotoluene; and oxyalkylene derivatives (alkylene oxide adducts) of trifunctional active hydrogen atom-containing compounds. It will be done. Among these, preferably OH
Polypropylene glycerol has an equivalent weight of 500 or less, more preferably 300 or less.

The amount of (C) or (D) or (E) used is usually 10 to 70%, preferably 20 to 40%, based on the weight of the total polyol. (C) or (D) or (E)
If the amount is less than 10%, the desired foam with a large hysteresis loss cannot be obtained. If it exceeds 70%,
In the case of (C), the curing properties of the foam become extremely poor, and in the cases of (D) and (E), the hardness of the foam increases and the soundproofing performance deteriorates.

As the organic polyisocyanate used in the present invention, those conventionally used in the production of urethane foam can be used. For example, aliphatic polyisocyanates (hexamethylene diisocyanate, nate), cycloaliphatic polyisocyanates (hydrogenated diphenylmethane diisocyanate, inphorone diisocyanate, etc.), aromatic polyisocyanates [toluene diisocyanate (
T DI ) diphenylmethane diisocyanate (
MDI) and mixtures thereof. Among these, aromatic diisocyanates are preferred, and TDI and MDI are particularly preferred. These polyisocyanates are crude polyisocyanates,
For example, crude TD■, crude MDI [crude diaminophenylmethane: a condensation product of formaldehyde and an aromatic amine or a mixture thereof; a mixture of diaminodiphenylmethane and a small amount (for example, 5 to 20% by weight) of a trifunctional or higher functional polyamine; etc. phosgenated product: polyallyl polyisocyanate (PAPI)], or modified polyisocyanate, such as liquid MDI (carposiimide modification, trihydrocarbyl phosphate modification, etc.) or excess polyisocyanate (TDI, MDI, etc.), and a polyol. It can be used as the obtained free isocyanate-containing prepolymer, or they can be used in combination (for example, a modified polyisocyanate and a prepolymer are used in combination). Particularly preferred among these is a mixture of TDI and crude MDI.

Examples of the blowing agent include water and/or other blowing agents, and specific examples include water, trichloromonofluoromethane, and methylene chloride. The amount used may be the amount used for foaming general ureta foam.

In addition, if necessary, catalysts (tertiary amines, organic tin compounds, etc.), surfactants (silicone surfactants, etc.),
The foaming reaction can be carried out in the presence of other auxiliaries.

If necessary, pigments, fillers, flame retardants, solvents, thixotropic agents, etc. can also be added.

The method for producing polyurethane foam may be the same as the conventional method, and both the fly-shot method and the prepolymer method (semi-prepolymer method) can be applied, but the one-shot method is preferable.

When making polyurethane foam, the equivalent ratio of NGO10H is usually 0.4 to 0.9, and if the equivalent ratio of NGOloH is less than 0.4, the curing properties of the foam deteriorate. If the equivalent ratio of NGOloH is greater than 0.9,
Soundproofing performance in the medium frequency range deteriorates.

Foaming is carried out so that the foam density is usually 20 Gkg/m' or less, preferably 100 kg/m' or less. When the foam density is greater than 200 kg/m'', the soundproofing performance is poor and economic efficiency is lacking.

[Example] The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto. Parts in the examples are parts by weight.

The components used in the Examples and Comparative Examples are as follows.

(1) Polyol Polyol A: A polyether polyol with a primary OH content of 80% and a molecular weight of 5,000 obtained by sequentially adding PO and EO to glycerin.

Polyol B: A polyether polyol with a primary OH content of 83% and a molecular weight of 16.000 obtained by sequentially adding PO and EO to sucrose.

Polyol C: 2 acrylonitrile in polyol A
Polymer polyol obtained by 0% polymerization.

Monool A: A monool with a molecular weight of 1200 obtained by adding PO to butanol.

Monool B: A monool with a molecular weight of 1200 obtained by sequentially adding PO and EO to butanol.

Diol A: Polypropylene glycol with a molecular weight of 400 obtained by adding PO to propylene glycol.

Triol A: Polyether polyol with a molecular weight of 1000 obtained by adding PO to glycerin.

(2) Additive Additive A: 2 moles of a monool with a hydroxyl value of 47 obtained by adding PO to butanol, and 2,4-TDI
A mixture of 80% and 2.6-TDI 20% (hereinafter referred to as
(abbreviated as TDI-80) at 80℃ [NGO content 0.1% or less, viscosity (25℃)
3000cps].

(3) Foam stabilizer L-5809: Silicone foam stabilizer manufactured by Nippon Unica ■.

(4> Catalyst U-CAT 1000: Tetramethylhexamethylene diamine manufactured by San Abro ■.

DABCO83LV: Dipropylene glycol solution of triethylene diamine manufactured by Air Products.

Examples 1 to 4 and Comparative Examples 1 to 2 According to the foaming formulation (parts) listed in Table 1, the polyol was mixed with a sucrose-based polyfunctional polymer polyol, a polymer polyol, triethanolamine (hereinafter abbreviated as TEA), and water. After premixing , foam stabilizer, and catalyst, TDI-80 and crude M
Incyanate blended with DI at 80:20 was added, stirred vigorously for 8 seconds, and poured into an aluminum mold (85×85×2 an) at 50-60° C. for foaming.

After curing at 100° C. for a predetermined period of time, the resulting polyurethane foam was demolded and its physical properties and soundproofing performance were tested. The results are shown in Table 2.

The soundproofing test was conducted in accordance with JIS A-1416r "Method for Measuring Sound Transmission Loss in a Laboratory", and the measurement results are shown in Table 2.

The physical property test method and units are as follows.

Total density (kg/m'): Foam weight/apparent volume tensile strength of foam (kg/ayf): JIS
K 6301 Elongation (%) 'JIS
K-6301 tear strength (kg/cm): J
IS K-6382 Compressive strength (kg/314cm2
): JIS K-6382 compression set (%'
) JIS K-6382 breathability (ft3/
m1n) Measured using a Dow airflow measuring device.

(The test piece is 50X 50X 25ovo) [Effects of the Invention The manufacturing method of the present invention has the following effects.

1. Compared to conventional similar foams, the injection-demolding time is significantly shortened, allowing for mold foaming with good curing properties and high productivity.

2. As shown in the sound transmission loss test results, a foam with excellent soundproofing properties was obtained. In particular, the characteristics in the medium frequency region near 1000 Hz are excellent.

3. A low-density foam was obtained without reducing the soundproofing effect.

Claims (1)

[Claims] 1. A method for producing polyurethane foam by reacting an organic polyisocyanate and a polymeric polyol in the presence of a blowing agent, a catalyst, and other additives, comprising: (1) at least one of the polymeric polyols; A polyol (A) containing a terminal polyoxyethylene chain having a functional group number of 5 or more and an equivalent weight of 1000 or more [However, (A) is a polyol (A_1) having an internal random polyoxyalkylene chain.
), and/or block polyoxyalkylene polyol (A_2)] and/or modified with an ethylenically unsaturated monomer (A) is used in an amount of 20% by weight or more, and (2) the equivalent amount of NCO/OH is used. Ratio is 0.4-0.9
(3) A method for producing polyurethane foam, characterized in that the foam density is 200 kg/m^2 or less. 2. In a method for producing polyurethane foam by reacting an organic polyisocyanate and a polymeric polyol in the presence of a blowing agent, a catalyst, and other additives, (1) at least a portion of the polymeric polyol has a functional group number of 5; Polyol (A) containing a terminal polyoxyethylene chain having an equivalent weight of 1000 or more [However, (A) is a polyol having an internal random polyoxyalkylene chain (A_1
), and/or block polyoxyalkylene polyol (A_2)] and/or modified with an ethylenically unsaturated monomer (A) in an amount of 20% by weight or more and an OH equivalent of 2000 based on the weight of the total polyol.
10 to 70% of the following monools or diols or triols with an OH equivalent of 500 or less are used, and (2) the NCO/OH equivalent ratio is 0.4 to 0.9 (3) the foam density is 200 kg/m^ A method for producing polyurethane foam characterized by having a polyurethane foam of 2 or less