JPS5867713A - Foamed material - Google Patents

Abstract

PURPOSE:A foamed material, prepared by mixing an isocyanate terminated prepolymer with a chemical substance having the water of crystallization in place of water as a foaming agent and curing agent together, capable of adjusting the pot life, and having improved applicability. CONSTITUTION:A chemical substance, e.g. Na2SO4.10H2O or Na2SO4.xH2O,X <10, capable of releasing water of crystallization at atmospheric pressure and 100 deg.C or below is mixed with an isocyanate-terminated prepolymer obtained by reacting a compound having active hydrogen atoms, e.g. a polyester, used in preparing a polyurethane with an excessive equivalent of polyisocyanate, e.g. aromatic, aliphatic and alicyclic polyisocyanate, and the resultant mixture is then foamed and cured to give the aimed foam.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an isocyanate resin foam. For more details, see Chemicals with water of crystallization and terminal isocyanate prepoly! The present invention relates to a foam with good workability and a highly adjustable pot life, which can be applied or injected onto a flat surface or one surface and foamed and cured by simple mixing using -.

Due to its excellent physical properties, incyanate resin foam is used as a soft 7-ohm urethane foam for vehicles, furniture seats, cushions, bedding, and clothing, and as a hard urethane foam for synthetic wood, including insulation materials for refrigerators, refrigerators, and building materials. Furthermore, it is used in a wide range of areas, including synthetic leather made by coating foam, and semi-rigid urethane foam, also called microcellular elastomer, used in shoe soles and the like.

This is because the isocyanate resin foam has the advantage that its elastic modulus can be freely adjusted by changing the molecular skeleton structure, crosslink density, composite with reinforcing material, expansion ratio, and foam shape.

That is, the molecular skeleton depends on the type of polyisocyanate, polyol, boriaone, and other compounds (hereinafter referred to as active hydrogen compounds) having a hydrogen atom (hereinafter referred to as active hydrogen) that can react with isocyanate F. From the combination K of molecular weight and number of active hydrogens in the molecule, reinforcing material,
By mixing a filler, the elastic modulus specific to the isocyanate resin can be freely adjusted. In addition, the foaming ratio and foam shape can be freely adjusted depending on the foaming curing conditions such as the type of foaming agent, the amount added, the reaction temperature, and the reaction rate. That is,
As the foaming ratio increases, the elastic modulus decreases, and the more the foam shape becomes large cells, elliptical cells, and open cells, the smaller the elastic modulus becomes, and the elastic modulus increases in the case of small cells, spherical cells, and closed cells.

In addition, the reason why the physical properties can be adjusted over a wide range is that incyanate has a high reactivity with active hydrogen compounds, and can be easily polymerized at room temperature or by relatively gentle heating.However, isocyanate resin foams are Since the resin formation reaction and the foaming reaction proceed in parallel, it is important to mix the polyisocyanate and the active hydrogen compound, and it is necessary to mix them quantitatively and regularly within the To conversion time. A mixer is required.

If the amount is insufficient or the mixing is insufficient, the degree of polymerization will be hindered and the rounding properties will be extremely reduced, making it impossible to obtain a resin and/or foam.

This round, incyanate resin foam is produced in a factory that is easily equipped with equipment. Some Ogai foaming equipment, such as spray foaming, has been developed, but it requires a heavy foaming machine.

In order to prevent insufficient quantitative determination and insufficient mixing, a method has been developed in which a prepolymer prepared by preliminarily resolving polyisocyanate and an active hydrogen compound has been developed.

For example, a terminal isocyanate prepolymer is synthesized from polyols, polyamines, etc. and polyisocyanate in excess of their active hydrogen equivalents, and this prepolymer is mixed with water or a low molecular weight active hydrogen compound having at least two functionalities. Compared to the one-shot method, it is now possible to create foams even with relatively rough mixing.

This method can foam even with rough stirring, so it is suitable for on-site construction in this respect, but the reaction rate between isocyanate and active hydrogen is highly temperature dependent and is an exothermic reaction. The reaction starts immediately when the mixture is mixed, and the amount remaining in the mixing container and turning into a resin is larger than that of the mixed and coated or injected area, which is a drawback.

One way to apparently lengthen the pot life is to reduce the active isocyanate content of the inocyanate-terminated prepolymer. According to this method, it is possible to take more than 10 hours from the start to the completion of the reaction, but the imbalance between the resin forming reaction and the foaming reaction causes the generated gas bubbles to burst, making it impossible to obtain a foam with good rolling properties.

According to the research results of the present inventors, in order to obtain a foam with good properties, it is necessary to convert the resin into a resin within 2 hours, preferably within 1 hour, to the extent that air bubbles can be retained even if the pot life is extended. be.

Another 19 methods for apparently lengthening the pot life include suppressing the activity of free isocyanate in terminal incyanate prepolymers, such as blocking with phenols and adding chlorine-based (e.g. evabenzoyl chloride) inhibitors. However, the former requires heating at high temperatures (for example, 140 to 160°C with a phenol block) to activate the isocyanate after coating or injection, while the latter suppresses overall reactivity and shortens the pot life. If it is added for a long time, it is difficult to form a resin even after coating or injection, and it has the disadvantage of requiring heating as a way to compensate for this, so it has not been put to practical use in formulations for obtaining foams.

In this respect, the prepolymer foaming method, which allows foamed resin to be formed by rough stirring, has poor workability in terms of pot life and has not been put to practical use.

In view of the current situation, the inventors of the present invention have conducted intensive research into a formulation that provides a foam with a long Bot 2 life and a good quality.
The inventors have discovered that the pot life can be freely adjusted by using a chemical substance having water of crystallization in place of water, which is a blowing agent and curing agent for terminal isocyanate prepolymers, and has thus arrived at the present invention.

That is, the present invention provides a foam made by foaming and curing a mixture of a chemical substance having water of crystallization and an incyanate-terminated prepolymer, and the pot life of the foam production can be reduced by 111 seconds. It made things possible. Normally, isocyanate-based resin foams require strict quantification of incyanate and active hydrogen, but when the chemical substance with water of crystallization of the present invention is used as a blowing agent and curing agent, even three times the theoretically required amount is required. It is possible to obtain a good foam even with a ratio of 10 times, and even with rough quantitative measurement and rough mixing, it has become possible to foam on-site.

In the present invention, by selecting the type of chemical substance that has water of crystallization, the pot life can be made different depending on the ease of releasing crystallized water and the ability to attract water. When a chemical substance that easily releases crystal water is used, the pot life is short, and when a chemical substance that is difficult to release crystal water is used, the pot life is long. The pot life can be set according to the rounding work conditions, and on-site workability is significantly improved. It has a pot life of at least 45 minutes, preferably 10 minutes, which is necessary for direct 4iI on-site foaming at the construction site, and completes the foaming and curing (resinization) reactions at low temperatures (without special temperature control in a natural environment). KII to obtain a foam with good elasticity
Particularly preferred is a chemical substance having water of crystallization used as a blowing agent/curing agent for the i-terminal incyanate prepolymer that starts releasing water at 100° C. or lower when measured alone in the atmosphere.

Chemical substances with water of crystallization used in the present invention are A.
z2(so,), 1saao% (NH4) 2 days o
, -Mu Ja (Sun 04) 3'24H20, K, SO, ・A
72(80,), 24H20%Ha, EIO, -1 0, Mg80.・7H20, Mn80.・7B, 0,
Fe80. -711.0.0ulilO, -5'H20
etc. In addition to these, any known chemical substances having water of crystallization can be used.

In addition, it is not limited to the nine chemical substances that have the maximum amount of crystallization water that the chemical substance can have, but also includes chemical substances that are in the process of absorbing or discharging water, that is, those that are in equilibrium movement due to environmental changes, and those that are in an equilibrium state. Among these, Na , SO, -10H, O, Na280. -x
H,O(X10) is a chemical substance with water of crystallization that is easy to obtain, has little toxicity, is cheap and easy to use.

The terminal isocyanate prepolymer used in the present invention is a polyisocyanate having at least two isocyanate groups, a carbodiimide-modified polyisocyanate, an isocyanurate-modified polyisocyanate, etc., and at least two or more of each rice-based polyisocyanate. polyols, polyamines, having active hydrogen of
It can be obtained by a normal terminal isocyanate prepolymer synthesis method, in which one or more active hydrogen compounds such as water are reacted in a proportion such that the total isocyanate amount is in excess of the total hydrogen equivalent.

Any of Polyincyanate's aromatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates used in the production of terminal incyanate prepolymers may be used, such as 1.5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, etc. isocyanane), 4
94'-diphenyldimethylmethane diisocyanate,
di- and tetraalkyldiphenylmethane diisocyanate), 4,4'-dibenzyl isocyanate, 1,! I
-phenylene diisocyanate, 1,4-phenylene diisocyanate,! , 4 or 2.6-) lylene diisocyanate, butane-1,4-diisocyanate, hexane-1,6-diisocyanate, dicyclohexylmethane diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, lysine diisocyanate, and other diisocyanates. Polyisocyanates such as -1-methylbenzo-2,4,6-triisocyanate, biphenyl-2,4,4'-triisocyanate, triphenylmethane triisocyanate F1 polyphene; polymethyl polyisocyanate, chlorine Examples include phosphorus-containing isocyanates, brominated incyanates, and phosphorus-containing isocyanates. Of course, known polyisocyanates other than those exemplified can also be used.

It goes without saying that these polyisocyanates may be used alone or in combination.The active hydrogen compound used in the production of the terminal isocyanate prepolymer of the present invention must have at least two isocyanate-reactive hydrogen atoms (active hydrogen atoms). (hydrogen), amino group, thiol group, or -
) In addition to compounds containing Jk boxyl groups, compounds containing hydroxyl groups, compounds containing 2 to 4% active hydrogen, etc. Known active hydrogen compounds commonly used in polyurethane production, such as polyesters and polyethers. , polyether polyols, polythioethers, polyacetals, polyester aodos, polycarbonates, polybutadiene glycols, etc. may be used alone or in mixtures.

Terminal isocyanate prepo IJ used in the present invention?
- is carried out in the presence or absence of a solvent. When aromatic polyisocyanates are used for active hydrogen compounds, a reaction temperature of 1S0 to 100 °C is selected, and when aliphatic and cycloaliphatic polyisocyanates are used, 5
0~1! A reaction temperature of IO° C. is used.

In the production of terminal isocyanate prepolymers, the amount of polyisocyanate is preferably selected so that all active hydrogen groups that react with isocyanate groups are reacted, and the ratio of the total number of isocyanate groups to the total number of active hydrogen groups is is 1,0 :D, 02 to 1. O: O and S are preferred.

Even in this ratio, if the number of isocyanate groups in the polyisocyanate is 3 or more, or if the active hydrogen compound has 5 or more active hydrogen groups, the total number ratio of isocyanate groups to active hydrogen groups will be the same as that of the polyisocyanate! - should be prevented from gelling.

In addition, K for obtaining a well-formed foam at room temperature (natural environmental temperature Wt without temperature control) has a reactive isocyanate content of at least 2 m, and if gentle heating (e.g. 50 to 60°C) is possible, at least 1 m. is necessary.

In addition, terminal isocyanate prepoly! in which all polyisocyanates have reacted with active hydrogen compounds! - or a mixture of terminal incyanate prepolymer and free polyisocyanate.0 To obtain the foam of the present invention, a good foam can be obtained without adding a special reaction catalyst of isocyanate and active hydrogen. be able to. However, depending on the usage situation, catalysts known per se may be used, such as triethylamine, tributylamine, N-methylmorpholine, F-methylmorpholine,
y.

N,M',M'-nato2methylethylenediamine, pentamethyldiethylenetriamine, 1,4-diazabicyclo-(L212)-octane, bis-methyl-I-dimethylaminoethylpiperidine, bis-(dimethylaminoalkyl)-piperazine, M, M-dimethylbenzylamine, M, M-dimethylcyclohexylamine, N, M-
Diethylbenzylamine, bis-(M,N-diethylaminoethyl)-adipate, x, m, N', d-tetramethyl-1,5-butanecyamine, M,M-cy)thyl-
Various amines such as β-phenylethylamine, 1,2-dimethylimidazole, 2-methylimidazole, tin acetate (1), tin octoate (1), tin ethylhexanoate (1) & tin laurate (M), and tin (
b) Compounds such as dibutyltin oxide, dibutyltin dichloride, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate or dioctyltin oxide, dibutyltin dichloride, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate or dioctyltin diacetate,
Organometallic compounds such as dibutyltinmonoisolukabutlaurate can be used.

In order to obtain the foam of the present invention, a good foam can be obtained without special use of a surfactant that is normally used in the production of isocyanate resin foam. However, a surfactant known per se may be contained as necessary depending on the usage situation.

For example, a siloxane-polyoxyalkylene block copolymer surfactant represented by the following formula is used.

(^ Medium, a = 0 or 1, b = 5 to 10, C = 20
50, R = OR, and/or Hl and R' = alkyl group with 1 to 4 carbon atoms) RR (wherein a = 20 to 28, b-5 to 15.0 =
Q to 80, d=Q to 80, R=OH3 and/or Hl and R'-alkyl having 1 to 4 carbon atoms and/or acetyl and/or H. ) The foam of the present invention is produced not only by mixing a terminal incyanate prepolymer with a chemical substance having water of crystallization, but also by using water as a blowing agent and crosslinking agent, or by using other known molecular weight active hydrogen as a chain extender. It is also possible to use a compound or a blowing agent known per se, such as a volatile organic substance, in combination.

It goes without saying that the foams of the invention may contain colorants, granular or fibrous reinforcements, and fillers that are known per se.

The foam obtained according to the present invention is used, for example, as a heat insulating material, a soundproofing material, a loss-proofing material, a reinforcing material, a filler, a sealing material, and a foamed paint for buildings, automobiles, fixed or movable equipment.

Example-1 Glass 5! Attach a stirring blade, temperature needle, nitrogen gas blowing tube, and dropping funnel to a Yotsuro flask. Millionate MTI, + (manufactured by Nippon Polyurethane Industries Co., Ltd., carbodiimide modified 4,4'-) to a Yotsuro flask.
Diphenylmethane diisocyanate, viscosity at 20°C, 7
0c, p, s, Woo content 28.596) 1.
000 t was charged, nitrogen gas was blown into the flask, and PPG-IP-240 was heated at room temperature (20°C) while stirring.
(Manufactured by Mitsui Nichi Urethane Co., Ltd., glycerin paste polyether polyol, viscosity at 20°C 2400 c, p,
0, hydroxyl value 24.0) 3.18Of was added dropwise from the dropping funnel over 30 minutes. At the end of dropping, the temperature of the liquid was 25°C. The flask was heated with a mantle heater, and the temperature was raised to 50°C in 50 minutes.The temperature was then gradually raised to 80°C in 2 hours. Then, it was cooled to room temperature (20° C.) for 30 minutes.

The nine prepolymers obtained had a MOO content of 5.5-20 °C.
The viscosity is! 8,000 o, p, s, and 'fi
-O Massive Ha, 80. '1011.0 and powder Ma
s 8 oa (all manufactured by Wako Pure Chemical Industries, Ltd. Kinsha)
were mixed and ground in a mortar at a mixing ratio of 470- and 89f,
Granular sodium sulfate with a particle diameter of 0.5 cm was used.

The above-mentioned terminal Wo is attached to the polyethylene cup of 1j.

500t of prepolymer and 60f of the above granular sodium sulfate
was added, stirred by hand for 15 seconds using a stainless steel bowl with a length of 25 alk, a width of up to 2 and a thickness of up to 0.2, and half of the mixture was poured onto a K 5 wm thick iron plate within 1 minute. Sa5II
I applied it with a spatula so that it was JIIK.

Foaming started after 10 minutes at room temperature (15° C.) and almost completed within 1 hour. Furthermore, the uncoated mixture in the polyethylene cup became difficult to coat after 14 minutes.As a result of measuring the physical properties of the foam 24 hours later, the volume was 15.
0 times pJ # tension, compressive elastic modulus at 20°C is 1.2
0 Comparative Example-1 The granular sulfuric acid of Example-1 was a uniform foam at 111/s2) Water 25 instead of IJum
- was mixed and coated in the same manner as in Example-1.

The uncoated mixture in the polyethylene cup, which started foaming as early as 1 minute at room temperature (15°C) and finished foaming within 1 hour, became no longer coatable after 1.5 minutes. Ta.

As a result of measuring the physical properties of the foam after 24 hours, the volume was 13.
The compressive elastic modulus at 20℃ after 0 times expansion is 1.20 b
/cyi'' and a uniform foamed product Example-2 A 5! glass four-way flask was equipped with a stirring blade, a temperature needle, a nitrogen gas blowing tube, and a dropping funnel.

A Yotsuro flask was charged with 1,000 t of Millionate MR (crude polyphenylmethane polyisocyanate manufactured by Nippon Polyurethane Industries Co., Ltd., viscosity at 20°C 2200°p, S8, Woo content 30.9 inches), and nitrogen gas was blown into the flask. rP at room temperature (20℃) while stirring.
e-Dtox-2, ooo (manufactured by Mitsui Nisso Cretan Co., Ltd., polypropylene glycol, viscosity at 20°C 450
c, p, s, , hydroxyl value 56.1) 2040
F was added dropwise from the dropping funnel over 15 minutes. After the dropwise addition was completed, the liquid temperature was 22°C.

Heat the flask with a heating mantle for 50 minutes for 14 minutes.
The temperature was raised to ℃, then gradually heated to 90℃ in 2 hours.

Then, it was cooled to room temperature (20° C.) for 50 minutes. The obtained prepolymer had a Hoo content of 7.4 mm and a viscosity of 49.0000·p, a· at 20°C. 200 tons of natural sand containing 901 or more and Example-1
Add and mix granular sodium sulfate mop, and add the above prepolymer son t to this mixture to a length of 25 (to).
Stir by hand for 15 seconds using a stainless steel spatula with a width of 2aks and a thickness of 0.2as.
Apply with a spatula to a thickness of 351 Lll on the concrete board. &CQ foaming started after 1 s at room temperature (1 s° C.) and almost completed foaming in 1 hour. Moreover, it became difficult to coat the uncoated mixture in the polyethylene cup only after 16 minutes had elapsed.

After 24 hours, the physical properties of the foam were measured and found that the foam was 10.5 times larger and had a compressive modulus of elasticity of 3.10-/♂ at 20°C, indicating that it was a uniform foam.

Comparative Example 2 In place of the granular sodium sulfate used in Example 2, 60 liters of water was used and mixed and coated in the same manner as in Example 2.

Foaming started after 1.5 minutes at room temperature and was almost completed within 1 hour. Moreover, the uncoated mixture in the polyethylene cup became uncoatable after 2.5 minutes.

As a result of measuring the physical properties of the foam after 24 hours, the volume was 10.
When foamed 5 times, the compression modulus at 20°C is Is, 11
47s'' and a uniform foam.

Claims (1)

[Claims] 1. A foam formed by foaming and curing a mixture of a chemical substance having water of crystallization and an incyanate-terminated prepolymer. 2. The foam according to claim 1, wherein crystallization water of a chemical substance having crystallization water starts to be released at 100 C or less.