JPH01215817A - Production of polyurethane foam - Google Patents

Abstract

PURPOSE:To produce a polyurethane foam excellent in an sound-insulating effect, especially, in low- and medium-frequency ranges, by reacting an organic polyisocyanate with a polyol in the presence of an additive comprising a specified compound. CONSTITUTION:A polyurethane foam is produced by reacting an organic polyisocyanate (e.g., 2,4- and/or 2,6-tolylene diisocyanate) with a polyol (e.g., polybutadiene-polyol) in the presence of a blowing agent, a catalyst, a foam stabilizer and further a compound of the formula [wherein R is a residue of an isocyanate compound, A is an alkylene, Z is a residue of a monofunctional active hydrogen compound, X is O or NR1 (wherein R1 is H or a monovalent hydrocarbon group), m is an integer >=1, and n is 0 or an integer >=1]. The obtained foam is excellent in a sound-insulating effect over the entire frequency range and especially excellent in a sound-insulating effect in low- and medium- frequency ranges as compared with a conventional foam regarded as being effective for sound insulation, and can be provided as a molded foam of a complicated shape and as an integral expansion molding with another base.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing polyurethane foam with excellent soundproofing properties. More specifically, the present invention relates to a method for producing polyurethane foam that has excellent soundproofing properties, particularly in the low and medium frequency ranges.

[Conventional technology] Conventionally, polyol and organic polyisocyanate were used as a blowing agent,
A urethane prepolymer with viscous terminal inert groups (isocyanate groups of the urethane prepolymer is replaced with methanol etc.) to produce flexible polyurethane foam by a one-shot method in the presence of catalysts, foam stabilizers and other additives. Monohydric alcohol.

There is a known method for producing polyurethane foam that has soundproofing and vibration damping properties by adding polyol (deactivated with monohydric carboxylic acid or secondary amine) (Japanese Patent Application Laid-open No. 1983-1999).
205115).

[Problems to be Solved by the Invention] The foam to which the urethane prepolymer having terminal inert groups as described above is added has a viscosity of 25%.
If it is less than 50,000 cps at ℃, there is a drawback that the soundproofing performance deteriorates. Further, when added to polyol, the viscosity increases, and when foaming is performed using a foam, miscibility with isocyanate becomes poor, making it difficult to obtain a good foam.

[Means for Solving the Problems] The present inventors conducted research to find a method for producing polyurethane foam that has excellent soundproofing effects in the low and high frequency ranges and can be molded with high productivity using an ordinary foaming machine. As a result, they discovered that by using a compound obtained from a specific active hydrogen compound and polyisocyanate, a polyurethane foam with excellent soundproofing effects in the low and high frequency ranges could be obtained, and the present invention was achieved.

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 a foam stabilizer, the general formula: % formula %) [wherein R is an isocyanate compound] residue, A is an alkylene group, L is a residue of a monofunctional hydroxyl group-containing compound, Z is a residue of a monofunctional active hydrogen atom-containing compound, X is O or NR,
(R, represents H or a monovalent hydrocarbon group), m is an integer of 1 or more, and n is 0 or an integer of 1 or more. ] This is a method for producing polyurethane foam, characterized in that the reaction is carried out in the presence of the compound (a) shown below.

In general formula (1), a plurality of Z, A, L, and X.

2 may be the same or different.

In general formula (1), a monofunctional hydroxyl group-containing compound forming a residue [L-OHI includes a monohydric alcohol having 1 to 18 or more carbon atoms (e.g. methanol, ethanol, n- and 1so-propanol); .

aliphatic, cycloaliphatic and aromatic alcohols such as butanol, 2-ethylhexyl alcohol, cyclohexanol, benzyl alcohol, etc.; monohydric phenols (e.g. alkylphenols such as phenol, nonylphenol); and monofunctional active hydrogen atom compounds such as Includes alkylene derivatives (alkylene oxide adducts). As the monofunctional active hydrogen atom compound, the above-mentioned 1
Hydrolic alcohols, monohydric phenols, and other compounds having one active hydrogen atom in the molecule [secondary amines (e.g. di-C1-20 alkylamines such as monomethylpropylamine, di-n-butylamine, monomethylstearylamine, Heterocyclic amines such as morpholine), monovalent C1~
20 mercaptan, C1-20 monocarboxylic acid, and the like. Examples of alkylene oxides include alkylene oxides usually having 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms, such as ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as po), 1.2-, 2
．． 3-, 1.3- and 1,4-butylene oxide, etc., and combinations of two or more of these (random and/or block addition), and preferred are PO, E
O and a combination thereof. Oxyalkylene derivatives can be obtained by addition polymerizing alkylene oxides in a conventional manner. The number of moles of alkylene oxide added is usually 1 to 1 mole per mole of monofunctional active hydrogen atom-containing compound.
100 mol, preferably 4 to 25 mol. Among the monofunctional hydroxyl group-containing compounds, oxyalkylene derivatives are preferred, particularly those having a molecular weight of 100 to 3,000.

Examples of A include alkylene groups usually having 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms, such as ethylene, n- and 1so-propylene, and butylene groups.

R1 usually has 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms.
valent hydrocarbon groups such as alkyl groups such as methyl and ethyl;
Examples include aralkyl groups such as benzyl and aryl groups such as phenyl.

In the general formula (1), the monofunctional active hydrogen atom-containing compound [Z-H] forming the residue 2 includes the above-mentioned 1
Alcohols, monovalent phenols, secondary amines, monovalent mercaptans, monocarboxylic acids, primary monoamines (C
1 to 20 aliphatic, cycloaliphatic and aromatic monoamines, e.g. alkylamines such as propylamine, stearylamine, etc.).

In general formula (1), the isocyanate compound forming the residue R [R(NGO)m. . These include mono- and polyisocyanates. Examples of the polyisocyanate include organic polyisocyanates as described below [preferably 2,4- and/or 2,6-tolylene diisocyanate (TDI), diphenylmethane-4,4''- and/or -2,4''-diisocyanate; (MDI)]
and isocyanate-terminated prepolymers derived therefrom [e.g. polyhydric alcohols such as ethylene glycol, glycerin, pentaerythritol, alkanolamines such as jetanolamine, triethanolamine, or these compounds with alkylene oxides (preferably PO, EO and Polyfunctional active hydrogen atom-containing compounds (active hydrogen 1
An isocyanate-terminated urethane prepolymer obtained by reacting an excess organic polyisocyanate (preferably one having a molecular weight of 100 to 3,000 per unit); N
CO content: usually 2-3%.

Polyisocyanates such as (preferably 5-20%):
As a monoisocyanate, for example, Japanese Patent Publication No. 34-21
Examples include those described in Publication No. 4.

In general formula (1), man is usually 1 to 8 or more, preferably 2 to 4. m is usually 1-8, preferably 2-4, and n is 0-7, preferably 0.

The content of urethane groups in the compound of general formula (1) is usually 1 to 2
The content of oxyalkylene groups in the compound of general formula (1) is usually 10 to 90% by weight, preferably 35 to 80% by weight.

The compound of general formula (1) is an isocyanate compound ■[R
(NGO), +. ], an oxyalkylene ether (alkylene oxide adduct) of a monofunctional hydroxyl group-containing compound
Or its aminated product (reacted with ammonia to introduce an amino group) (side adduct) or its aminated product (reacted with ammonia to introduce an amino group) ■ [H-X-A-○-L ], or by reacting it with a monofunctional active hydrogen atom-containing compound (1) [H-X-Zl.

R(NGO)man + mH-X-A-0-L+ n H-X-ZZ, (NH-C○-X-Z)n It is preferable that the ratio of ■ and ■, and if necessary, the ratio of ■ is equal. , may be present in excess (for example, about 20% excess).

The order of these reactions is not particularly limited, and methods include a method in which these are reacted simultaneously, a method in which ■ and ■ or a part thereof are reacted, and then ■ and/or the remainder of ■ are reacted, and a method in which ■ and ■ are reacted.
Examples include a method of reacting , and then reacting .

In addition, in general formula (1), when the residue R is an isocyanate-terminated prepolymer, the organic polyisocyanate and polyol that are the raw materials, ■ and, if necessary, ■
can be reacted in any order. For example, in addition to a method of reacting an isocyanate group-terminated prepolymer with Finally, the general formula (1 ) can be produced.

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

Examples include polyether polyol, polyester polyol, polybutadiene glycol, castor oil, and polycarbonate diol.

Examples of polyether polyols include compounds having a structure in which an alkylene oxide is added to a polyfunctional compound containing an active hydrogen atom, such as a polyhydric alcohol, a polyhydric phenol, or a polycarboxylic acid. The polyhydric alcohols include dihydric alcohols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and neopentyl glycol, and glycerin, trimethylolpropane, pentaerythritol, sorbitol, Trivalent or higher polyhydric alcohols such as sucrose; polyhydric phenols include polyhydric phenols such as pyrogallol and hydroquinone, as well as bisphenols such as bisphenol A; condensates of phenol and formaldehyde (novolac), for example, US Pat. No. 3,265,641 Examples include polyphenols described in the specification. Also, examples of amines include ammonia;

and alkanolamines such as triethanolamine, isopropanolamine, and aminoethylethanolamine: C1 to C20 alkylamines; C2
~C6 alkylene diamines such as ethylene diamine,
Aliphatic amines such as propylene diamine, hexamethylene diamine, polyalkylene polyamines such as diethylene triamine, triethylene tetramine; aniline, phenylene diamine, diaminotoluene, xylylene diamine, methylene dianiline, diphenyl ether diamine and other aromatic amines; Alicyclic amines such as isophorone diamine and cyclohexylene diamine; aminoethyl piperazine and other special public patents
Examples include heterocyclic amines described in JP-A No. 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 of these active hydrogen atom-containing compounds may be used in combination. Among these, polyhydric alcohols are preferred. The alkylene oxide to be added to the active hydrogen atom-containing compound is an alkylene oxide having usually 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms, such as Eo, po, 1.2-
, 2.3-, 1.3- and 1.4-butylene oxide, etc. 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, EO and 1,4-
Butylene oxide (tetrahydrofuran).

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 ).

Polymer polyols include polyols obtained by polymerizing these polyols (polyether polyols and/or polyester polyols, etc.) and ethylenically unsaturated monomers (acrylonitrile and/or styrene, etc.) (for example, JP-A-54-1999-1). No. 101899 and those described in JP-A-54-122396).

In addition, polybutadiene polyols, hydroxyl group-containing vinyl polymers (acrylic polyols) such as JP-A-58-5
Natural oil-based polyols such as those described in No. 7413 and JP-A-58-57414 and castor oil can also be used.

Examples of the low-molecular polyol include the polyhydric alcohols mentioned above as raw materials for polyether polyols, and low-mole alkylene oxide adducts of the above-mentioned active hydrogen atom-containing compounds.

In addition to the polyol, other low-molecular active hydrogen atom-containing compounds (for example, the alkanolamines and polyamines mentioned above as raw materials for the polyether polyol) can be used in combination, if necessary.

The amount of compound (a) in the total amount of polyol (and other active hydrogen atom-containing compounds if necessary) is usually 5%.
It is preferably 20% or more, more preferably 30% or more.

The average number of functional groups of the entire polyol (and other active hydrogen atom-containing compounds if necessary) is usually 2 to 4, preferably 2.
．． 1 to 3. The (average) hydroxyl value of the entire polyol is usually 15-400, preferably 20-200.

As the polyisoleanate used in the present invention, those commonly used for polyurethane are used. For example, aromatic polyisocyanates having 6 to 20 carbon atoms (excluding carbon in the NC○ group) [2,4- and/or 2,6-
TDI, crude TI) I, 4,4'- and/or 2.
4'-MDI, crude MDI [crude diaminophenylmethane] formaldehyde and aromatic amine (aniline)
or a condensation product with a mixture thereof, a mixture of Nidiaminodiphenylmethane and a small amount (e.g. 5 to 20% by weight) of a trifunctional or higher functional polyamine]; phosgenated product of [poIJ aryl polyisocyanate (PAPI)], etc.); carbon number 2 to 18 aliphatic polyisocyanates [hexamethylene diisocyanate, anate, lysine diisocyanate, etc.]
; Alicyclic polyisocyanates having 4 to 15 carbon atoms (isoborone diisocyanate, dicyclohexyl diisocyanate, etc.); Aroaliphatic polyisocyanates having 8 to 15 carbon atoms [xylylene diisocyanate, etc.]; and modified products of these polyisocyanates. (Modified products containing urethane groups, carbodiimide groups, urea groups, allophanate groups, biuret groups, uretdione groups, uretonimine groups, isocyanurate groups, oxazolidone groups, etc.): and polyisocyanates; and mixtures of two or more thereof. Among these, preferred are 2,4- and 2゜6-TDI, and mixtures of these isomers;
, 4′- and 2.4′-MDI, and mixtures of these isomers, and urethane groups, carbodiimide groups, allophanate groups, urea groups, biuret groups, uretdione groups derived from these polyisocyanates,
It is a modified polyisocyanate group containing a uretonimine group, an isocyanurate group, and an oxazolidone group, and is an NGO
The content is usually 15-45%, preferably 20-35%.

In producing polyurethane foams using compound (a) according to the invention, water and/or volatile blowing agents are used as blowing agents. Examples of volatile blowing agents include halogen-substituted aliphatic hydrocarbon blowing agents (fluorocarbons such as trichloromonofluoromethane). Further, foaming can also be carried out by introducing a gas such as air during molding (air loading).

The amount of blowing agent used is such that the density of the resulting polyurethane foam is usually 0.015 to 0.2 g/cm 3 or more, preferably 0.03 to 0.15 g/cm 3 . The amount of water used is usually 6% or less, preferably 1 to 4.5%, based on the polymer polyol.

If the amount of water used exceeds 6%, the soundproofing effect will be significantly reduced; if it is less than 1%, the breathability of the polyurethane foam will deteriorate, which is not preferable. The amount of the halogen-substituted hydrocarbon blowing agent used is usually 20% or less, preferably 5 to 10%, based on the weight of the resin raw material. When performing air loading, 10% of the specific gravity of the resin raw material is used.
As mentioned above, it is desirable to introduce the gas so that the gas content is preferably 10 to 40%.

The NGO index used in the present invention is usually 60-120, preferably 70-100, particularly preferably 80-90. Also, excess isocyanate (as an index, e.g. 1
20 to 5000, preferably 150 to 100, can also be used to form a polyisocyanurate foam).

Catalysts used in the production of polyurethane foam include tertiary amines and organic tin compounds.

Organic lead compounds, etc.; Examples of foam stabilizers include surfactants (silicone surfactants, etc.).

When producing polyurethane foam, other auxiliaries and additives such as pigments, fillers, flame retardants, solvents, internal mold release agents, thixotropic agents, etc. may be added as necessary.

The content of compound (a) in polyurethane foam is usually 5
~200% weight%, preferably 20-50% by weight.

If (a) is less than 5%, a polyurethane foam with good soundproofing performance cannot be obtained, and if it exceeds 200%, the physical properties of the resulting polyurethane foam will be extremely poor.

The polyurethane manufacturing method may be the same as conventional methods, and either the wafshot method or the prepolymer method (quasi-prepolymer method) can be applied. A one-shot method is preferred. Foaming methods include slab method, mold method [hot mold method, H
It can be applied to any method such as R (high elasticity) molding method.

The polyurethane foam obtained in the present invention may be any of ultra-soft, soft, and semi-rigid foams, but ultra-soft and soft foams are particularly preferred.

[Example] The present invention will be described below with reference to Examples, but the present invention is not limited thereto. The parts shown in the examples represent 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.

20% acrylonidocyl in polyether polyol A
Polymer polyol obtained by polymerizing %.

(2) Additive Additive C: 2 moles of a monool with a hydroxyl value of 47 obtained by adding PO to butanol, and 2°4-TDI 8
A mixture of 0% and 20% 2.6-TDI (hereinafter referred to as TDI
-80) at 80℃ [
NGO content 0.1% or less, viscosity (25℃) 3000c
ps].

Additive D = po and EO in butanol 50:50
2 moles of a monool with a hydroxyl number of 47 obtained by adding a blend of 2800cps].

Additive E: 1 mol of diol with a hydroxyl value of 118 obtained by adding PO to propylene glycol and T'DI-
NGO content obtained by reacting 802 mol with 6.
2 moles of a monool with a hydroxyl value of 47 obtained by adding PO to butanol were added to 1 mole of a 5% prepolymer, and the mixture was reacted at 80°C [NGO content 0.1%].
Below, viscosity (25°C) 20000 cps].

Additive F: 1 mol of diol with a hydroxyl value of 118 obtained by adding Po to propylene glycol and TDI-8
NGO content 6.5 obtained by reacting with 02 mol at 80 ° C.
% of prepolymer, add 2 moles of methanol,
Reacted at 80°C [EO content 0.1X or less, viscosity (25°C) approximately 200,000 cps].

(3) Foam stabilizer 5RX-274C: Silicone stabilizer manufactured by Toray Silicone Co., Ltd.

(4) Catalyst U-catloooo: Tetramethylhexamethylene diamine manufactured by San-Apro Co., Ltd.

DABCO33LV: Dipropylene glycol solution of triethylene diamine manufactured by 17-Products.

Examples 1 to 3 and Comparative Examples 1 to 2 A polyol with additives dissolved therein, a polymer polyol, and triethanolamine (hereinafter abbreviated as TEA) were prepared according to the foaming formulation (parts) shown in Table 1.

After premixing water, foam stabilizer, and catalyst, TDI-80
An 80:20 blend of isocyanate and crude MDI was added, stirred vigorously for 8 seconds, and poured into an aluminum mold (85 x 85 x 2 cm) at 50 to 60°C to foam. Table 2 shows the test results for the physical properties and soundproofing performance of the polyurethane foam obtained after curing at 100°C for 5 minutes and demolding.
2 Shown in Figure 1.

The soundproofing test was conducted in accordance with JIS A141 r Laboratory Sound Transmission Loss Measurement Method, and the results are shown in Figure 1.

Table 1 Polyol A 90 90 90 90 90 Polyol B 10 10 10 10 10 Additive C30--- Additive D-30--- Additive E---30--- Additive F----30 TEA 1. 0 1.0 1.0 1.0 1
．． 0 water 3.0 3.0 3.0 3.0
3.0DABCO33LV O,20,20,20,
20,2U-catloooo 0.5 0.5 0.
5 0.5 0.5SRX-274C1,01,01,
01,01,0Table 2 Total density 67 68 66 67 73
Tensile strength 1.05 1.00 1.01 1.2
0 1.01 elongation 150 150 150.
147 140 tear strength 0.65 0.60 0
．． 60 0.80 0.60 Compressive strength 25% strain 6.0 6.2 6.5 12.1 11
．． 565% distortion 17.8 18.1 18.5 37
．． 1 30.9 Permanent set 6.5 6.3 6.0
3.2 2.5 Physical properties Test methods and units are as follows.

Total density (kg/m3): Foam weight/apparent volume tensile strength of foam (kg/cm2): JIS K-63
01 Elongation (%): JIS K-63
01 Tear strength (kg/cm): JISK-6
382 compressive strength (kg/314cm2): JIS
K-6382 permanent set (%): JIS
K-6382 [Effects of the Invention] According to the present invention, the following effects can be achieved by using an additive consisting of a compound represented by general formula (1) together with a polyol during the production of polyurethane foam.

1) Superior soundproofing effect in all frequency ranges compared to general foam.

2) Compared to conventional foam that is said to have a soundproofing effect,
Excellent soundproofing effect in the low and medium frequency range.

3) It is possible to mold foam into complex shapes, and it can also be easily molded and foamed with other base materials, so it has high utility value.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between frequency and sound transmission loss of the foams of Examples and Comparative Examples.

Claims (1)

[Claims] 1. In a method for producing polyurethane foam by reacting an organic polyisocyanate and a polyol in the presence of a blowing agent, a catalyst, and a foam stabilizer, the general formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (1) [Wherein, R is a residue of an isocyanate compound, A is an alkylene group, L is a residue of a monofunctional hydroxyl group-containing compound, Z is a residue of a monofunctional active hydrogen atom-containing compound, and X is O or NR_
1 (R_1 is H or a monovalent hydrocarbon group), m is 1
n is an integer of 0 or 1 or more. ] A method for producing polyurethane foam, characterized by carrying out the reaction in the presence of the compound (a) shown below. 2. (a) from 5 to 200% based on the weight of the polyol
The method according to claim 1, wherein the method is used.