JPH07196756A - Foaming composition - Google Patents

Abstract

PURPOSE:To obtain a foaming composition composed of a polyisocyanate compound, a compound containing plural active hydrogens and a foaming polymeric compound, free from yellowing of a foamed article, lowering of the ratio of closed cells, etc. CONSTITUTION:This foaming composition is composed of (A) a compound containing an isocyanate group in average of >=2 in the molecule (e.g. diphenylmethane diisocyanate), (B) a compound containing an active hydrogen in average of >=2 in the molecule (e.g. polyethylene glycol), preferably a polyether having a terminal amino group and an average molecular weight of 200-10000 and (C) a foaming polymeric compound (preferably, a polystyrene containing 1-10wt.% of a foaming agent).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to foamable compositions.
More specifically, when a polyisocyanate for forming a polyurethane (polyurea) is reacted with a polyol, a polyamine or the like to form a urethane bond (urea bond),
The present invention relates to a foamable composition effective for producing a novel and inexpensive heat insulating material by foaming a foamable polymer compound using generated heat of reaction.

[0002]

2. Description of the Related Art Polyurethanes are used in various fields such as paints, molding materials and heat insulating materials because of their excellent mechanical properties and good workability. In particular, a polyurethane foam has excellent heat insulating performance and is useful as a heat insulating material for energy saving.

As a method for producing the polyurethane foam, a method using a foaming agent such as Freon and a method utilizing carbon dioxide generated by the addition of water, which has been widely used in recent years, are known. There is.

[0004]

Among the methods for producing the polyurethane foam, a method using a foaming agent such as Freon is used because the foaming agent such as Freon to be used adversely affects the natural environment. Is gone,
Alternatives are being developed.

Although a method of using a foaming agent other than the foaming agent such as Freon, which has a bad influence on the natural environment, for example, a hydrocarbon-based foaming agent has been carried out, in the case of this method, it is difficult to obtain a homogeneous foam. There is a problem that the obtained foam has a low thermal conductivity.

Further, when a foam is produced by utilizing carbon dioxide generated by adding water, there are problems that resin burns occur and that the homogeneity of foam is poor and the closed cell ratio is low.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a part or most of the foam to be formed is a foamable polymer compound (polyethylene, polypropylene, polystyrene, poly). Pellets or particles such as vinyl chloride impregnated with a low boiling point organic compound) are foamed, and the remainder is formed from polyurethane to form a homogeneous, high-foamed foam. The compound (I) containing an average of two or more isocyanate groups in one molecule, the compound (II) containing an average of two or more active hydrogens in one molecule, and a foamable polymer compound ( III) and a novel foamable composition which has been hitherto unknown.

[0008]

EXAMPLES Compound (I) having an average of two or more isocyanate groups in one molecule (hereinafter, also referred to as compound (I)) used in the present invention is a compound well known in the field of polyurethane industry. is there.

Specific examples of the compound (I) include diphenylmethane diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate. These may be used alone or in combination of two or more. Further, these isocyanates may be used as a prepolymer obtained by reacting a hydroxyl group-terminated diol or triol under an isocyanate excess condition.

Specific examples of the prepolymer include those obtained by reacting hexamethylene glycol, ethylene glycol, propylene glycol, butanediol and the like with excess diphenylmethane diisocyanate or tolylene diisocyanate.

When the compound (I) as described above is at room temperature to 80 ° C.
From the viewpoint of workability, it is preferably liquid at the temperature of. For example, diphenylmethane diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and the like.

The number of isocyanate groups contained in the compound (I) has sufficient strength and the expandable polymer compound (I
From the viewpoint of generating the reaction heat necessary for foaming II), the number is 2 or more on average, but preferably 2 to 1 on average.
It is 0.

The number of isocyanate groups contained in one molecule is limited to an average value of 2 or more because the monoisocyanate compound is used to adjust the isocyanate equivalent weight and the physical properties of the reaction product. This is because they may be used together.

The compound (II) (hereinafter referred to as compound (I) used in the present invention containing an average of two or more active hydrogens in one molecule.
Also referred to as I)) is a well-known compound in the field of polyurethane industry.

Examples of the compound (II) include terminal hydroxyl group polyether, terminal hydroxyl group aliphatic polyester, terminal amino group polyether and the like. Of course, alkylene glycols such as ethylene glycol, propylene glycol, and tetramethylene glycol, and oligoethers such as diethylene glycol, dipropylene glycol, ditetramethylene glycol, triethylene glycol, and tripropylene glycol, in which these alkylene glycols are bonded by an ether bond. As a matter of course, the compounds may be used for adjusting the hydroxyl equivalent and adjusting the physical properties of the reaction product.

The average molecular weight of the terminal hydroxyl group polyether is preferably 200 to 20,000 from the viewpoint of handling (the viscosity is not too high), and 200 to 5,
000 is more preferable. Further, the number of hydroxyl groups per molecule is preferably 2 to 4 from the viewpoint of the strength of the obtained foam.

Specific examples of the terminal hydroxyl group polyether include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and a copolymer of ethylene oxide and propylene oxide. These may be used alone. You may use it as a mixture of 2 or more types.

The average molecular weight of the terminal hydroxyl group polyester is preferably 200 to 10,000 from the viewpoint of handling (the viscosity is not too high), and 200
Those of up to 2,000 are more preferable. Further, the number of hydroxyl groups per molecule is preferably 2 to 4 from the viewpoint of the strength of the obtained foam.

Specific examples of the terminal hydroxyl group polyester include ring-opening polymers of ε-caprolactone, condensates of glycols such as ethylene glycol and 1,4-butanediol with adipic acid.

Further, the average molecular weight of the terminal amino group polyether is preferably 200 to 10,000 from the viewpoint of handling (the viscosity is not too high),
Those of 200 to 5,000 are more preferable. Also, 1
The number of amino groups per molecule is preferably 2 to 3 from the viewpoint of strength and reactivity.

The amino group includes --NH ₂ and --NH.
It may be any of R, but in the case of -NH ₂ , since there are two active hydrogens, one amino group becomes 2 equivalents, and
In the case of HR, it becomes 1 equivalent.

The compound (II) as described above may be used alone or in combination of two or more kinds.

The composition of the present invention contains the compound (I) and the compound (II). The ratio of the compound (I) and the isocyanate group of the compound (I) is the equivalent of the hydroxyl group or amino group of the compound (II). It is preferable to use it so that the ratio is in the range of 1: 1 to 1: 0.7, preferably 1: 1 to 1: 0.8. If the proportion of isocyanate groups used is higher than this range, the cured product will become too hard, and the isocyanate groups that are undesirable for safety and hygiene will tend to remain. It is difficult to obtain a hardened product.

The compound (II) to be used is a compound (II) containing an average of two active hydrogen atoms in one molecule, in order to obtain desired physical properties such as strength and elongation. The compound (II) containing an average of three active hydrogens in one molecule may be appropriately mixed, and the compound (II) having a large average molecular weight and a compound having a small average molecular weight may be appropriately mixed.

In order to make the reaction product of the compound (I) and the compound (II) flexible and have a high elongation, both the compound (I) and the compound (II) have a large average molecular weight,
In each case, it is preferable to use those having nearly two reactive groups. On the other hand, in order to obtain a hard and low elongation, both compound (I) and compound (II) have a small average molecular weight. Also, it is preferable to use one having a large number of reactive groups.

When a urethane bond (urea bond) is formed by the reaction of the compound (I) and the compound (II), it is preferable to use a catalyst in order to accelerate the reaction.

Examples of the catalyst to be used include tin compounds such as dibutyltin laurate and dibutyltin maleate, amines such as triethylamine and diazabicycloundecene.

Compound (I) and compound (I
The amount of the catalyst used is generally about 0.1 to 5 parts with respect to 100 parts by weight of I) (parts by weight, the same applies hereinafter).

In the composition of the present invention, the foamable polymer compound (III) is used together with the compound (I) and the compound (II).
Is contained.

The foamable polymer compound (III) comprises a polymer material and a foaming agent, and the foaming agent is used as a foaming agent necessary for foaming the composition of the present invention. In addition, the polymer material plays a role of holding a foaming agent while it is present as a composition, and plays a role of improving the characteristics of the urethane foam when foamed.

The foamable polymer compound (II
As the polymer material constituting I), the ability to absorb and retain the foaming agent is high, and the heat generated during the reaction between the compound (I) and the compound (II) causes the foaming agent to expand, resulting in continuous foaming, and It is preferable that the material has a good affinity with polyurethane.

Specific examples of such a polymer material include:
Examples thereof include polyethylene, polypropylene, polystyrene and polyvinyl chloride, which have a softening point of about 50 to 130 ° C. and have a good affinity with a foaming agent as described later. These may be used alone or in combination of two or more.

As the foaming agent contained in the polymer material, an organic compound having a boiling point of about −20 to + 120 ° C., which does not adversely affect the natural environment like Freon, is preferable.

Specific examples of such a foaming agent include butane, pentane, cyclopentane, cyclohexane and toluene.

The expandable polymer compound (III) containing the polymer material and the foaming agent as described above is contained in the polymer material in an amount of 1 to 20% (% by weight, hereinafter the same), preferably 1 to 1
One containing a foaming agent of about 0% can be mentioned. When the content of the foaming agent is less than the above range, the foaming becomes insufficient, and it becomes difficult to obtain a foam having desired properties, and when it is more than the above range, The polymeric material is difficult to stably absorb and retain the foaming agent, and the foam tends to be weak.

The average particle size of the foamable polymer compound (III) is not particularly limited, but is 0.1 to 2 mm.
Something is used.

The foamable polymer compound (II
As a specific example of I), polystyrene beads containing 1 to 10% of a foaming agent such as butane (average particle size of 0.1 to 0.1)
2 mm) is preferable in terms of workability and foamability.

The foamable polymer compound (II
I) is 10 to polystyrene beads suspended in water.
It is produced by a method such as impregnating butane under a pressure of 50 kg / cm ² .

The amount of the foamable polymer compound (III) used is preferably 5 to 300 parts, more preferably 10 parts with respect to 100 parts in total of the compound (I) and the compound (II).
The range is up to 200 parts. When the amount used is less than the above range, only a low expansion ratio is likely to be obtained, and when the amount used is more than the above range, the reaction heat necessary for obtaining a sufficient foam may be obtained. In many cases, it is difficult to form a foam having sufficient characteristics.

The composition of the present invention contains a flame retardant, if necessary.
Additives for improving the interfacial adhesion between the expanded particles obtained by expanding the expandable polymer compound and the polyurethane, inorganic fillers and the like may be added as appropriate.

As the flame retardant, a halogen-based flame retardant,
For example, decabromodiphenyl ether, trischloropropyl phosphate, etc., as additives for improving interfacial adhesion, for example, bisphenol-A-diglycidyl ether, phenol resin, etc., and as inorganic fillers, for example, silica, alumina, calcium carbonate, talc. , Clay, etc. The amount of each used may be determined according to the purpose.

The method for preparing the composition of the present invention is not particularly limited, but it may be prepared by adding the foaming polymer compound (III) to a mixture of the compound (I) and the compound (II), It may be prepared by adding a lumber of the compound (I) or the compound (II) to a mixture of one of the compound (I) or the compound (II) and the foamable polymer compound (III),
It may be prepared by mixing the compound (I), the compound (II) and the foamable polymer compound (III) at once.

When the composition of the present invention is prepared and then stored as a composition, after addition of the foamable polymer compound (III), the temperature should not be so high that foaming starts, and Compound (I) and compound (I
It is necessary to avoid such a high temperature that the reaction of I) starts. On the other hand, when the composition is prepared and subsequently foamed, such a limitation is eliminated.

Next, the composition of the present invention will be explained based on examples, but the present invention is not limited to these examples.

Example 1 In a container, 30 parts of a triol-type polyoxypropylene having a molecular weight of 3,000 and 5 parts of diphenylmethane diisocyanate were reacted at room temperature under a nitrogen stream for 1 day. 5 parts of polystyrene beads having an average particle size of 1 mm and containing 6% butane were added and heated to 50 ° C. To this system, 6 parts of a triol type polyoxypropylene having a molecular weight of 3,000 and 1 part of dibutyltin laurate were added and uniformly mixed, and a part of the mixture was transferred to a glass container.
A cured product containing a foam of polystyrene beads was obtained, and the total volume expanded three times.

Example 2 In Example 1, a phenol resin (a novolac-type phenol 5-6mer) was used together with polystyrene beads.
The same treatment as in Example 1 was carried out except that a part was added. In the obtained cured product, the foamed styrene beads were firmly bound to each other by the matrix resin, and peeling at the interface was not observed even when the cured product was unrolled.

Example 3 30 parts of triol type polyoxypropylene having a molecular weight of 600 and diphenylmethane diisocyanate 4 were placed in a container.
0 part was reacted for one day at room temperature under a nitrogen stream. 6 in this system
% Of butane, 20 parts of polystyrene beads having an average particle size of 1 mm, and a phenol resin (used in Example 2) 3
Parts were added. Further, 1 part of dibutyltin laurate and 30 parts of triol type polyoxypropylene having a molecular weight of 600 were added, and a part thereof was transferred to a glass container and allowed to stand for several hours. The volume of the obtained cured product expanded about 20 times. .

[0048]

The composition of the present invention is a novel type of foamable composition which has not existed before. By using this composition of the present invention, it is possible to eliminate the disadvantages of the foam, such as the burning of the foam and the decrease in the closed cell ratio, which occur when the polyisocyanate and water are reacted to foam.

Claims (6)

[Claims] 1. A compound (I) containing an average of 2 or more isocyanate groups in one molecule, a compound (II) containing an average of 2 or more active hydrogens in one molecule, and a foamable polymer compound (I).
II) and a foamable composition containing. 2. The compound (II) having an average of two or more active hydrogens in one molecule has an average molecular weight of 200 to 20,000.
The composition according to claim 1, which is a polyether having a terminal hydroxyl group. 3. A compound (II) containing an average of two or more active hydrogens in one molecule has an average molecular weight of 200 to 10,000.
The composition according to claim 1, which is an aliphatic polyester having a terminal hydroxyl group. 4. The compound (II) containing an average of two or more active hydrogens in one molecule has an average molecular weight of 200 to 10,000.
The composition according to claim 1, which is a polyether having a terminal amino group. 5. The composition according to claim 1, wherein the polymer compound constituting the foamable polymer compound (III) is polyethylene, polypropylene, polystyrene, polyvinyl chloride alone or a mixture thereof. 6. The foamable polymer compound (III) is 1 to
Polystyrene containing 10% by weight of blowing agent.
The composition as described.