WO2022269684A1

WO2022269684A1 - Foam booster, premix solution including same, composition for polyurethane foam molding including these, and polyurethane foam with improved hydrophobicity

Info

Publication number: WO2022269684A1
Application number: PCT/JP2021/023397
Authority: WO
Inventors: 誠基田村; 裕之稲垣
Original assignee: ダウ・東レ株式会社
Priority date: 2021-06-21
Filing date: 2021-06-21
Publication date: 2022-12-29

Abstract

[Problem] To provide a foam booster, etc., endowed with major advantages not found in the prior art such as having excellent stability, handling workability, and foamability of a premix liquid, having excellent cost and work efficiency in building applications, etc., having a fine cell structure of the foam obtained, that is suitable for applications such as insulating materials, and that can markedly improve the hydrophobicity of a polyurethane foam in comparison to conventional foam boosters. [Solution] Provided are: a foam booster containing a silicone polyether copolymer having a specific structure for a water-foamed polyurethane spray foam system including a) a specific polyether polyol, b) a polyisocyanate, c) a curing catalyst, and d) water, which is the major foaming agent; a premix solution including the same; a composition for polyurethane foam molding including these; and a polyurethane foam having improved hydrophobicity and the use thereof.

Description

Foam booster, premix solution containing same, composition for forming polyurethane foam containing same, and polyurethane foam with improved hydrophobicity

The present invention provides a silicone polyether having a specific structure for a water-blown polyurethane spray foam system comprising a) a specific polyether polyol, b) a polyisocyanate, c) a curing catalyst, and d) water as the primary blowing agent. Regarding foam enhancers containing copolymers, etc., the foam enhancers have excellent hydrophobicity improving effects on polyurethane foams, particularly flexible polyurethane foams, obtained by the same system. In the following description, "foam" means a polyurethane foam unless otherwise specified.

BACKGROUND ART Conventionally, a method of constructing an insulation layer by on-site foaming has been carried out on the insulation construction parts of various buildings such as houses, refrigerated warehouses, and tank facilities. In recent years, the need for further cost reduction has increased, and low-density foam formulations with a high foaming ratio (that is, a large number of water-using parts) have spread. From a cost-in-use perspective, sellers of these foamed polyurethane systems are looking for foam stabilizers that can produce larger volumes of foam with the same dosage. Commercial products are also available as suitable for residential thermal insulation spray foam systems.

Such a foamed polyurethane heat insulating layer is usually positioned between the outer wall of a house or the like and the inner wall of the room. Therefore, in cold seasons such as winter, when warm air containing moisture inside the room moves into the heat insulating layer, it may be cooled from the outer wall side and cause condensation. In addition to the concern that dew condensation may cause the generation of mold, it also leads to the deterioration of polyurethane. In addition, such a foamed polyurethane heat insulating layer can be used as a sound absorbing layer that effectively absorbs the impact sound on the upper floor by positioning it between the upper floor and the lower ceiling of the house. This is because the foamed polyurethane is not a closed cell type but a continuous type based on an open cell structure, so sound easily enters the cells and is efficiently attenuated within the cells, resulting in high soundproofing. .

On the other hand, polyether-modified silicones can be designed with various structures and average molecular weights, and the EO wt. %, size, introduction of a lipophilic group to the silicone main chain, variation in the structure of the silicone main chain, the site of introduction of a modifying group, modification with two or more different polyether groups, etc. properties, affinity to urethane foam systems, etc. can be controlled. Therefore, polyether-modified silicones can be used in all polyurethane foam formulations such as rigid foams, semi-rigid foams, HR (high elasticity) foams (hereinafter sometimes simply referred to as "HR foams"), flexible foams, and microcellular foams. It has been known for a long time that it is useful as a surfactant (foam stabilizer) for controlling or stabilizing foam.To date, many varieties have been commercially manufactured and sold, greatly contributing to the development of the polyurethane foam industry. Contributing.

However, blow-in-place spray foam for high water add-on building insulation is considered a relatively new technical area in the long history of the polyurethane foam industry. That is, within the scope of the present inventors' investigation, the chemical structure of the polyether-modified silicone foam stabilizer, the performance of the foam stabilizer in the spray foam formulation, the correlation with the obtained foam properties, etc. have been detailed so far. No reports have been made (Patent Documents 1 to 10). Specifically, Patent Documents 1 and 2 do not disclose a silicone foam stabilizer modified with a polyether chain having a terminal hydroxyl group. Patent Documents 3 to 10 disclose PO wt. Some examples of silicones modified with polyether chains with a large percentage and hydroxyl groups at the ends have been tried to apply to various foam formulations, but poor performance has been reported, such as being treated as a comparative example. There were many cases. Alternatively, in some cases, compositions containing the silicone were prepared, but performance was not confirmed by actual foaming evaluation. Also, there is no mention of spray foams in any of the prior art documents, and the foam formulations carried out and the foams obtained were completely different from the formulations for spraying and the foams obtained therefrom. For example, in a 100-fold expansion spray foam formulation using water as the main foaming agent, the number of parts of water used is usually 10 to 40 parts per 100 parts of polyol, which is extremely large, and is characterized by the fact that a low-density foam can be obtained. , the range of the number of parts to be added of water used in the formulations of various foam types in the prior art is only 1.0 to 6.5 parts, which is very different from the content of the present invention. In addition, general-purpose foam stabilizers for flexible slab foam, which are currently being diverted to residential thermal insulation spray foam systems, are suitable for increasing foam volume, but there is a need to lower the moisture permeability or water absorption of the foam. I have not been able to respond. Furthermore, in these prior documents, there is no knowledge of the present invention that the hydrophobicity of the urethane foam itself can be improved by selecting a specific chemical structure for the polyether-modified silicone used as a foam stabilizer for urethane foam. is not mentioned, tested or confirmed.

As described above, in Patent Documents 1 to 10, there is no explanation about the spray foam formulation, so the number of parts added with water is large, and the on-site foaming spray foam for building insulation is characterized by using a polyol for flexible urethane foam. Prescription considerations were also not made. Therefore, neither the chemical structure of the polyether-modified silicone foam stabilizer, the performance of the foam stabilizer in the spray foam formulation, nor the correlation with the properties of the obtained foam, etc. have been provided. Furthermore, in this application, 1) compatibility with premix systems, 2) imparting a larger foam volume, and 3) imparting a finer open cell structure are generally considered to be performances expected of foam stabilizers. There is no description or suggestion of 4) the technique of lowering the moisture permeability or water absorbency of the foam itself (or improving the hydrophobicity of the foam), which is currently required. For this reason, it has been difficult for those skilled in the art to anticipate the technical effects of the existing technology, as there is no effective approach for improving the hydrophobicity of urethane foam by selecting the chemical structure of the foam stabilizer.

Under such background art, there is a need for a technology that solves the above technical problems, uses a specific raw material/foaming/curing system, and provides a polyurethane foam that satisfies the above requirements. ing. There is also a need for techniques to effectively improve the hydrophobicity of polyurethane foams.

U.S. Pat. No. 3,817,822 U.S. Pat. No. 3,398,104 U.S. Pat. No. 3,669,913 U.S. Pat. No. 4,478,957 U.S. Pat. No. 4,529,743 Japanese Patent No. 3135318 (JP-A-5-117352) U.S. Pat. No. 5,489,617 U.S. Pat. No. 6,071,977 (Patent No. 4,366,470) US Patent No. 8436064 (Patent No. 5743544) European Patent Application Publication No. 3530703 (International Publication No. 2018-074257)

The present invention has been made to solve the above problems, and by using a large number of water addition parts and a small amount of foam stabilizer (foam enhancer), it is possible to form a large volume foam at a construction site or the like. It is particularly suitable for water-blown polyurethane spray foam systems, and has excellent compatibility with premix systems. An object of the present invention is to provide a foam enhancer which has a fine cell structure and can remarkably improve the hydrophobicity of the resulting foam. In the present subject, the foam is preferably flexible urethane foam.

Further, the present invention provides premix solutions containing the suds booster and suitable for water-blown polyurethane spray foam systems, polyurethane foam-forming compositions containing the suds booster, and compositions obtained by using the suds booster. It is an object of the present invention to provide a polyurethane foam (particularly, a flexible polyurethane foam) which is particularly improved in hydrophobicity and uses thereof (heat insulating material/sound absorbing material, etc.).

Furthermore, based on the unexpected discovery that the hydrophobicity of urethane foam is significantly improved by selecting the chemical structure of the silicone polyether copolymer, the present invention provides a foam enhancer containing the silicone polyether copolymer. It is an object of the present invention to provide a method for improving the hydrophobicity of polyurethane foams, which is not limited to a particular spray foam system, and a method for improving the hydrophobicity.

Although the present invention solves the above problems, the present inventors have also discovered new problems with polyurethane foam-forming compositions and polyurethane foams prepared therefrom. That is, as a recent market need for polyurethane foam (hereinafter sometimes abbreviated as "urethane foam" or "foam") material, demand for low emission properties, that is, "low emission characteristics" is increasing. This is a required property characterized by the amount of components such as chemical substances generated or volatilized from the polyurethane foam being quantitatively small. (Organic Compound)), to prevent sick house allergies, etc., the amount of chemical substances emitted from the foam to the outside over time is small (= Low Emission Of Chemical Compound), volatile components from the foam used inside the car It is sometimes expressed as a requirement that it is difficult for dust to adhere to the window glass and cause fogging (= Low Fogging). The substantive meaning is almost the same in that there is less

A further object of the present invention is to provide a flexible polyurethane foam that satisfies such requirements for Low Emission/Low VOC and is obtained from the composition for forming a polyurethane spray foam.

As a result of intensive studies, the present inventors found general formula (1):

{wherein each R independently represents a monovalent hydrocarbon group having 1 to 16 carbon atoms selected from alkyl, aryl and aralkyl groups,
Each X is independently one or more of the formula: -C _k H _2k O-(C ₂ H ₄ O) _p (C ₃ H ₆ O) _q (C ₄ H ₈ O) _r -Y represents the polyether group of
Y is 100 mol % of H groups, or consists of 75 mol % or more of H groups and 25 mol % or less of other groups selected from C1-C4 alkyl or acetyl groups;
m, n, k, p, q, and r are numbers satisfying the following conditions.
12≦(m+n)≦230,
10≦m,
2≦n,
n≦m,
3≤k≤4,
p, q, and r have a formula weight of the polyether group moiety represented by X in the range of 1400 to 4000,
{sum of the formula weights of the oxypropylene group moiety represented by ( _C3H6O )q and the oxybutylene group moiety represented by ₍ _C4H8O )r}/ _{ ₍ _C2H4O )p The sum of the formula weights of the oxyethylene group moieties represented by)} is the ratio value Z,
It is a number that satisfies the condition (51/49)≤Z≤(95/5).
However, in X in the formula, a polyether group having a structure where 1≤p and q=r=0 is excluded. }
The inventors have found that the above problems can be solved by a foam enhancer containing a silicone polyether copolymer represented by the following, and have completed the present invention. The suds booster is particularly suitable for use in water-blown polyurethane spray foam systems having specific configurations, and is not limited to specific spray foam systems, to significantly improve the hydrophobicity of polyurethane foams. can be done.

Furthermore, the present inventors have discovered premix liquids for water-blown polyurethane spray foam systems containing the above-described foam boosters, polyurethane foam-forming compositions containing them, and hydrophobically enhanced soft foams prepared therefrom. The present inventors have found that the above problems can be satisfactorily solved by a polyurethane foam, a flexible polyurethane foam having Low Emission/Low VOC characteristics, or a heat insulating material/sound absorbing material, and have arrived at the present invention.

According to the present invention, the number of parts to be added with water is large, and it is suitable for on-site foaming spray foam formulations such as building insulation applications using polyols for flexible urethane foam, excellent compatibility with premix systems, and can be used in small amounts A foam enhancer capable of forming a large-volume foam suitable for building insulation, etc., having a fine cell structure, and significantly improving the hydrophobicity of the resulting foam. can be provided. Further, it is possible to provide a premix liquid for a polyurethane spray foam system and a composition for forming a polyurethane spray foam containing the foam enhancer.

Further, according to the present invention, a flexible polyurethane foam with improved hydrophobicity obtained from the composition for forming polyurethane spray foam and uses thereof, in particular, the flexible polyurethane foam having low emission/low VOC properties, heat insulation comprising these We can provide the material or sound absorbing material.

Furthermore, according to the present invention, in the production of polyurethane foams other than water-blown polyurethane spray foams, there is provided a method for significantly improving the hydrophobicity of polyurethane foams by using the foam enhancer to improve the hydrophobicity of the foams. can be done.

In addition, the foam enhancer of the present invention is excellent in quality and environmental compatibility, and can be manufactured at a lower cost than the foam stabilizer for flexible slab foam currently being diverted to water foam spray foam. is possible. Thus, the present invention allows manufacturers of foam stabilizers to have the option of supplying high volumes to the market at lower prices than in the past, while manufacturers of premixes and foam systems We are able to provide end customers and markets with excellent premix liquids for polyurethane spray foam systems and polyurethane spray foam forming compositions, and both contribute to the sound development of society and industry and pursue appropriate profits. The degree of freedom that can be compatible with is increased.

[Silicone polyether copolymer and foam enhancer containing the same]
First, the silicone polyether copolymer, which is the main component of the foam enhancer according to the present invention, will be described in detail. As described above, the present invention is based on the unexpected discovery that the hydrophobicity of urethane foam is significantly improved by selecting the chemical structure of the silicone polyether copolymer, and that the silicone polyether copolymer has a specific composition. The structure of the silicone polyether copolymer is one of the characteristic features of the present invention. .

More specifically, the silicone polyether copolymer according to the present invention is represented by the following general formula (1).
General formula (1):

In general formula (1), each X is independently represented by the formula: -C _k H _2k O-(C ₂ H ₄ O) _p (C ₃ H ₆ O) _q (C ₄ H ₈ O) _r -Y Represents one or more polyether groups,
Y is 100 mol % of H groups, or consists of 75 mol % or more of H groups and 25 mol % or less of other groups selected from C1-C4 alkyl or acetyl groups;
m, n, k, p, q, and r are numbers satisfying the following conditions.
12≦(m+n)≦230,
10≦m,
2≦n,
n≦m,
3≤k≤4,
p, q, and r have a formula weight of the polyether group moiety represented by X in the range of 1400 to 4000,
{sum of the formula weights of the oxypropylene group moiety represented by ( _C3H6O )q and the oxybutylene group moiety represented by ₍ _C4H8O )r}/ _{ ₍ _C2H4O )p The sum of the formula weights of the oxyethylene group moieties represented by)} is the ratio value Z,
It is a number that satisfies the condition (51/49)≤Z≤(95/5).
However, X in the formula does not include a polyether group having a structure where 1≤p and q=r=0. That is, the polyether group portion represented by X in the formula may be a mixture of polyether chains having two or more different average chemical structures, but the polyoxyalkylene portion is composed only of polyoxyethylene groups. It does not contain bases. This is because, as will be described later, the technical effects of the present invention cannot be exhibited if the proportion of the portion derived from oxyethylene units in the polyether portion in the present invention is high.

The formula weight is the sum of the product of the atomic weight and the number of atoms based on the chemical formula and composition formula. calculated based on the average chemical structure (structure identified by nuclear magnetic resonance spectroscopy with mainly 13C and 1H nuclides), the polyether group moiety represented by X, the oxypropylene group moiety, and the oxyethylene group The formula weights of the moieties and their sums.

In the above general formula (1), each R is preferably independently selected from an alkyl group having 1 to 10 carbon atoms, an aryl group, an aralkyl group, methyl, ethyl, n-propyl, n-butyl, i linear or branched alkyl groups such as -butyl, n-pentyl, i-pentyl, 2-methylbutyl, n-hexyl and n-octyl; phenyl; phenethyl or phenylisopropyl. Industrially particularly preferred, R is a methyl group.

In the general formula (1), X is a polyether group having a polyoxyalkylene structure bonded to silicon atoms, the formula:
—C _k H _2k O—(C ₂ H ₄ O) _p (C ₃ H ₆ O) _q (C ₄ H ₈ O) _r —Y
defined by Here, k is the number of carbon atoms of the alkylene group bonded to the silicon atom, and from the viewpoint of industrial practicality, 3≦k≦4, more preferably k=3.

Y is a terminal group of a polyoxyalkylene structure, 100 mol% of which is an H group (hydrogen atom), or 75 mol% or more of an H group and 25 mol% or less of a C1-C4 alkyl or acetyl group. consists of the basis of Preferably, Y is 100 mol % hydrogen atoms.

In the polyether group portion represented by X, p, q, and r are the average number of oxyethylene units, oxypropylene units, and oxybutylene units that constitute the polyoxyalkylene structure, and The formula weights of the oxypropylene group moiety represented by {(C ₃ H ₆ O) q and the formula weight of the oxybutylene group moiety represented by (C ₄ H ₈ O) r are within the range of 1400 to 4000. The sum of the ratios}/{the sum of the formula weights of the oxyethylene group moieties represented by (C ₂ H ₄ O)p)} is
It is a number that satisfies the condition (51/49)≤Z≤(95/5).

Here, when the ratio value Z exceeds (95/5), the oxypropylene group moiety represented by (C ₃ H ₆ O)q and the oxybutylene group represented by (C ₄ H ₈ O)r Hydrophobicity derived from the base portion becomes excessive, making it difficult for the silicone polyether copolymer to make the polyether polyol and a large amount of water compatible, which tends to cause poor stability of the premix liquid and poor foaming. Conversely, if the value of the ratio Z is less than (51/49), i.e. the number of oxyethylene units is equal or higher than the sum of the oxypropylene and oxybutylene units, then the The compatibility with the polyol for flexible urethane foam used in the on-site foaming spray foam formulation becomes insufficient, and it tends to be difficult to obtain a stable premix liquid, resulting in the failure to obtain the desired foam stabilizing effect. effect may not be achieved. The polyether group portion represented by X may be a mixture of polyether chains having two or more different average chemical structures, but a polyether having terminal hydroxyl groups and composed only of an oxyethylene portion It does not contain any groups. Such highly polar hydrophilic groups are not suitable because they are less compatible with the polyol.

More preferably, the X group does not contain oxybutylene units and has the formula:
—C ₃ H ₆ O(C ₂ H ₄ O) _p (C ₃ H ₆ O) _q —H
wherein the formula weight of the X group is in the range of 1500 to 2500, and the ratio Z satisfies the condition of (54/46)≦Z≦(80/20).

The oxyethylene units, oxypropylene units, and oxybutylene units contained in the polyether group X may have a block-type copolymer structure or a random-type copolymer structure. is more preferred.

As for the alkylene group bonded to the silicon atom and having 3 to 4 carbon atoms, and the alkylene portion constituting the oxypropylene unit or oxybutylene unit, even if it is a linear alkylene group, isopropylene group or isobutylene It may also be a branched isoalkylene group, such as a group.

In the general formula (1) above, m and n are degrees of polymerization of each siloxane unit of the side chain (Rake) type silicone polyether copolymer, and 12 ≤ (m + n) ≤ 230, 10 ≤ m, 2 ≤ n, a number in the range n≦m. In particular, the numbers are preferably in the range of 40≦m≦90 and 2≦n≦8.

The silicone polyether copolymer according to the present invention has a
i) Excellent compatibility with polyols for flexible urethane foam, and can form a stable premix solution
ii) It has excellent foamability and can form a large-volume foam (= foam volume) at a building manufacturing site even if it is used in a small amount, so it is excellent in terms of cost and work efficiency in building applications.
iii) The resulting foam has a fine cell structure and is suitable for use as a heat insulator/sound absorber.
iv) Combined with the major advantage not found in the prior art of being able to significantly improve the hydrophobicity of polyurethane foams (especially flexible polyurethane foams) compared to conventional foam enhancers, and It satisfies the requirements of Low Emission/Low VOC, which are of high importance in building applications.

Specifically, in the preferred silicone polyether copolymer described above, since the ratio of the lipophilic portion derived from the oxypropylene unit or the oxybutylene unit is high with respect to the formula weight of the entire polyether portion, Excellent compatibility with polyols for flexible urethane foam used in on-site spray foam formulations for thermal insulation. Therefore, it is advantageous in obtaining desirable foam-stabilizing effects such as expansion of convenience due to improved stability of the premix liquid and provision of a large foam volume and a fine cell structure.

In addition, since the proportion of the portion derived from oxyethylene units is low with respect to the formula weight of the entire polyether portion, the preferred silicone polyether copolymer described above does not solidify even at low temperatures, and has a low viscosity. It does not become too high, and the handleability after production is also improved. Furthermore, the use of the above preferred silicone polyether copolymer as a foam stabilizer for the spray foam can remarkably improve the hydrophobicity of the obtained urethane foam in addition to the foam enhancing effect.

[Synthesis of silicone polyether copolymer]
Such a silicone polyether copolymer can be obtained by a known method of hydrosilylating a polyether compound having an alkenyl group at one end of the molecular chain and an organohydrogenpolysiloxane in the presence or absence of any solvent. Can be synthesized.

Preferably, the silicone polyether copolymer according to the invention has the following general formula (1H):

an organohydrogenpolysiloxane represented by {wherein R has the same definition as above, and m and n are the same numbers as above};
The following general formula (2):
C _k H _2k-1 O—(C ₂ H ₄ O) _p (C ₃ H ₆ O) _q (C ₄ H ₈ O) _r —Y
{Wherein, k, p, q and r are the same numbers as above, Y is the same definition as above, and C _k H _2k-1 is a straight or branched chain having a carbon-carbon double bond It is a silicone polyether copolymer obtained by a hydrosilylation reaction with a polyether compound having an alkenyl group at one end of the molecular chain represented by }.

At this time, the oxyethylene units, oxypropylene units, and oxybutylene units contained in the polyether compound represented by the general formula (2) may have a block-type copolymer structure or a random-type copolymer structure. can be taken, but a random type structure is preferred. The silicone polyether copolymer according to the present invention can also be obtained by reacting two or more different polyether compounds with the organohydrogenpolysiloxane. Structure of 0: Does not include polyether compounds in which the polyoxyalkylene portion is composed only of the polyoxyethylene portion. The reason for this is that polyether groups having terminal hydroxyl groups and consisting only of oxyethylene moieties have too strong a polarity, so that polyols for flexible urethane foams used in on-site expansion spray foam formulations for building insulation cannot be used. This is because, as a result of hindering the compatibility of , it is likely to be difficult to obtain a stable premix liquid, and the desirable foam-stabilizing effect is also impaired.

When carrying out the above hydrosilylation reaction, the ratio of [substance amount of carbon-carbon double bonds in the polyether compound/substance amount of silicon-bonded hydrogen atoms in the organohydrogenpolysiloxane] is 1.0 to A range of 2.0 can be exemplified. That is, when synthesizing the silicone polyether copolymer according to the present invention, it is preferable to use an excessive amount of the polyether compound. More specifically, the above ratio is preferably in the range of 1.05 to 1.75, more preferably in the range of 1.20 to 1.60. The reason for this is that a portion of the terminal alkenyl groups of the polyether compound undergoes internal transfer during the hydrosilylation reaction and ceases to participate in the reaction. This is because it is necessary to keep the ratio excessive. Therefore, such a silicone polyether copolymer is generally obtained as a mixture of the product silicone polyether copolymer and an unreacted polyether compound, and is represented by general formula (1) according to the present invention. A foam enhancer having a hydrophobicity-improving effect containing a silicone polyether copolymer is constituted.

Since these components are highly compatible with each other, the foam enhancer containing the silicone polyether copolymer and having the effect of improving hydrophobicity is usually obtained as a transparent or almost transparent homogeneous liquid. Industrially, the polyether compound represented by the general formula (2) is produced by addition polymerization of ethylene oxide, propylene oxide, etc. in the presence of an alkali catalyst using an unsaturated alcohol such as allyl alcohol or allyl glycol as a starting material. However, depending on the level of water removal from the reaction system, it may contain diols at both ends as impurities. Therefore, such a double-ended diol compound, such as a PEG/PPG copolymer, may be further contained in the foam enhancer according to the present invention.

When performing the above hydrosilylation reaction, the progress of the reaction may be affected by trace impurities originally contained in the polyether compound or the organohydrogenpolysiloxane, by-products due to deterioration over time, and trace contaminants in the reactor. may be delayed. In such a case, appropriate measures such as adding a catalyst, raising the reaction temperature slightly higher than usual, extending the reaction time, or adding a reaction solvent for the purpose of improving the compatibility between the raw materials may be taken to prevent the reaction. It is desirable to control the process until the residual Si—H groups in the system are below the detection limit. Remaining Si—H groups may cause the generation of combustible hydrogen gas when the foam enhancer is blended into a premix system. Since it is known to deteriorate the foam stabilizing performance of silicone polyether copolymers used as foam stabilizing agents, the residual amount of Si—H groups should be approximately 30 wt. ppm or less, and 10 wt. ppm or less, and 2.5 wt. ppm or less is particularly preferred. Incidentally, the silicone polyether copolymer partially containing such a small amount of Si—H groups is not represented by the general formula (1) on the text, but industrially, it is considered to be substantially the same type. Included in the present invention.

Here, a reaction solvent is often not necessary, but when using a general organic solvent, aromatic hydrocarbon solvents such as toluene and xylene, alcohol solvents such as isopropyl alcohol; cyclohexane, n-heptane, methyl Selection from aliphatic saturated hydrocarbon solvents such as cyclohexane is preferred for industrial production. In general, these highly volatile reaction solvents need to be removed from the product system by stripping as soon as they have completed their role, such as the completion of the hydrosilylation reaction. Among them, toluene and xylene belong to the so-called BTX solvents and have been widely used for the production of silicone polyether copolymers used as foam stabilizers. Since it is difficult on a production machine scale, it cannot meet the needs of the current polyurethane industry, which requires strict BTX management. Therefore, if necessary, select an appropriate one from isopropyl alcohol or a saturated hydrocarbon solvent with an average number of carbon atoms in the range of 6 to 11, considering cost, safety, convenience during production, etc. It is desirable to use

Specific examples of such saturated hydrocarbon solvents having an average number of carbon atoms in the range of 6 to 11 include methylcyclohexane, n-heptane, heptane mixtures, heptane (commercial grade), isooctane, 2,2,4- trimethylpentane, octane mixture, ethylcyclohexane, dimethylcyclohexane, n-hexane, isohexane, hexane mixture, cyclohexane, 2-methylpentane, 2-methylheptane, 3-methylheptane, Isopar E (C7-C9 saturated hydrocarbon mixture), Isopar C (C7-C8 saturated hydrocarbon mixture), IP solvent 1016 (C6-C9 saturated hydrocarbon mixture), Isopar G (C10-C11 saturated hydrocarbon mixture) and the like. Among these, C7 saturated hydrocarbons typified by methylcyclohexane, n-heptane, heptane mixtures, and heptane (commercial grade) are preferred.

The foam booster according to the invention may additionally optionally comprise a diluent h') a polyalkylene glycol or derivative thereof which is liquid at 25°C. By using such component h'), the viscosity and the like of the foam enhancer of the present invention can be adjusted without adversely affecting the function as a foam stabilizer or surfactant, and convenience during use and handling workability ( handling) can be improved. In addition, component h') may be used in addition to the foam enhancer for the purpose of adjusting the hydroxyl value in the polyurethane foam-forming composition, that is, controlling various physical properties such as the crosslink density and strength of the polyurethane foam. .

The catalyst for the hydrosilylation reaction is not particularly limited as long as it can promote the hydrosilylation reaction. As a hydrosilylation reaction catalyst, many metals and compounds have been known so far, and a suitable one can be selected from them and used for the production of the component e) according to the present invention. Specific examples of hydrosilylation reaction catalysts include particulate platinum adsorbed on a silica fine powder or carbon powder carrier, chloroplatinic acid, alcohol-modified chloroplatinic acid, Speyer's catalyst, olefin complex of chloroplatinic acid, chloride Coordination compounds of platinic acid and vinyl siloxanes, Karstadt catalysts, platinum black, palladium, and rhodium catalysts may be mentioned. These catalysts are dissolved or dispersed in toluene, xylene, ligand compounds of catalysts, alcohols, other suitable polar solvents, raw materials for reaction such as polyethers and diluents, etc., according to standard methods, and introduced into the reaction system. can do.

The amount of hydrosilylation reaction catalyst used is an effective amount, and is not particularly limited as long as it is an amount that promotes the synthesis reaction of the silicone polyether copolymer, which is the main component of the foam enhancer according to the present invention. Specifically, the sum (total 100% by mass), the amount of metal atoms in the catalyst is 0.5 to 100 ppm, preferably 3 to 30 ppm by mass of platinum metal atoms. If the content of the hydrosilylation reaction catalyst is less than the lower limit of the above range, the addition reaction may be insufficient. may have an adverse effect on transparency, such as coloring of

Conditions for the hydrosilylation reaction can be arbitrarily selected according to the type of raw materials and the presence or absence of a solvent. For example, the reaction can be completed by adding a small amount of an antioxidant such as tocopherol (vitamin E) and heating and stirring for a certain period of time at room temperature to 120°C, preferably 50 to 100°C, in an inert gas atmosphere such as nitrogen. . The antioxidant may be added after hydrosilylation is completed. The reaction time can be selected according to the reaction scale, amount of catalyst used and reaction temperature, and is generally in the range of several minutes to several hours. In addition, the reaction may be carried out under reduced pressure for the purpose of improving quality and productivity, and not only a batch process but also a known semi-continuous or continuous production process can be applied.

The end point of the hydrosilylation reaction can be confirmed by the disappearance of Si—H bond absorption by infrared spectroscopy (IR) or the disappearance of hydrogen gas generation by the following alkaline decomposition gas generation method. The amount of hydrogen gas generated can also be determined by analyzing silicon-bonded hydrogen atoms (Si—H) in the organohydrogenpolysiloxane, which is the reaction raw material, by the same method.

In the alkali decomposition gas generation method, a solution obtained by dissolving a sample in toluene or IPA and a mixed solution of 28.5% by mass of caustic potash in ethanol/water are allowed to react at room temperature, and the generated hydrogen gas is collected in a collection tube. It is a method of measuring the volume.

In addition, since the silicone polyether copolymer, which is the main component of the foam enhancer according to the present invention, has a structure modified by a polyether group having a terminal hydroxyl group, a side reaction during the hydrosilylation reaction: dehydrogenation and Suppression of acetal formation is important. When chloroplatinic acid or a solution thereof is used as a catalyst, an appropriate amount of a buffering agent represented by alkali metal carboxylates such as potassium acetate, potassium propionate and sodium acetate is added to the reaction system before the start of the main reaction. It is better to keep These may be added to the reaction system as solids (powder), dissolved or dispersed in a polar solvent such as methanol and then added to the reaction system, or may be added to the reaction system in advance by It is possible to exhibit the effect by dissolving or dispersing it in a polyether compound having an alkenyl group at its end. Generally, when these side reactions occur, the reaction system thickens, and in severe cases, gelation may occur. Use of a reaction solvent is effective in reducing such a situation. The timing of adding the buffer is preferably before the start of the hydrosilylation reaction (main reaction). has the effect of However, if the amount of buffering agent added is too large, the progress of the main reaction will be slowed down, or other side reactions that start with the cleavage of the silicone main chain during the stripping process will easily occur, so care must be taken. The optimum amount of buffering agent to be added is the amount just enough to neutralize the amount of acid in the system, or a slight excess.

The foam enhancer according to the present invention may be gradually oxidized by oxygen in the air and deteriorate. In order to prevent this, an antioxidant such as phenols, hydroquinones, benzoquinones, aromatic amines, or vitamins can be added to increase the oxidation stability, which is preferable. As such an antioxidant, for example, in addition to vitamin E described above, BHT (2,6-di-t-butyl-p-cresol), vitamin C, and the like may be used. However, from the viewpoint of reducing Emission from polyurethane foam, it is important to select vitamin E and other high-molecular-weight antioxidants. At this time, the amount of the antioxidant used is in the range of 10 to 1000 ppm, preferably 50 to 500 ppm, based on the weight of component e).

[Reduction of low-molecular-weight siloxane]
In the foam enhancer according to the present invention, the content of low-molecular-weight siloxane having 20 or less silicon atoms is preferably 5000 ppm (weight) or less, particularly preferably 2000 ppm (weight) or less. If this value exceeds 5,000 ppm, when the foam enhancer is used as a foam stabilizer for polyurethane foam, it may contaminate the surrounding members where the polyurethane foam is installed and cause contact failure in electrical and electronic devices. have a nature. Such low-molecular-weight siloxanes include cyclic ones and straight-chain ones. dimethylsiloxane and linear dimethylsiloxane oligomers represented by the formula CH3[(CH3)2SiO]mSi(CH3)3, where m is an integer from 1 to 10; Some methyl groups are partially substituted with other organic groups. More specific examples of such low-molecular-weight siloxanes include octamethyltetrasiloxane, decamethylpentacyclosiloxane, and both-terminal trimethylsiloxy group-blocked dimethylsiloxane oligomers. The content of such low-molecular-weight siloxane can be measured by analysis using, for example, a gas chromatography analyzer. Although the method for reducing low-molecular-weight siloxane is not limited, it is usually done industrially by a stripping operation. Purification to remove low-molecular-weight siloxanes is desirable. Alternatively, the low-molecular-weight siloxane may be removed during the hydrosilylation reaction or after completion of the reaction.

[Water-blown polyurethane spray foam system]
The foam booster containing the above silicone polyether copolymer of the present invention is applied to a water-blown polyurethane spray foam system comprising a) to d) below.
a) one or more polyether polyols having an average number of hydroxyl groups in the molecule of 2 to 4, having repeating units composed of oxypropylene groups, and having a number average molecular weight in the range of 1000 to 6000;
b) polyisocyanates,
c) a curing catalyst,
d) Foaming agent that is water Sum of polyether polyol and other polyol components as component a) in the same system Range of 10 to 40 parts by mass per 100 parts by mass

Furthermore, the water-blown polyurethane spray foam system described above may contain at least one or more polyol components other than a') component a) polyether polyol. In this case, d) the blowing agent, which is water, is added in an amount of 10 to 40 parts by mass per 100 parts by mass of the sum (=total amount) of component a) and component a').

Furthermore, the water-blown polyurethane spray foam system described above may optionally include f) a nonionic surfactant (silicone polyether covalent agent according to the present invention) as long as it does not impair the technical effects of the present invention. including organic surfactants and emulsifiers that do not correspond to polymers), g) flame retardants, h) other additives: for example, foam stabilizers for urethane foam other than the foam enhancer according to the present invention, diluents, Chain extenders, crosslinkers, secondary amounts of non-aqueous blowing agents, cell openers, fillers, reinforcing agents, pigments, dyes, colorants, antioxidants, antiozonants, UV stabilizers, antistatic agents, bactericides and antibacterials, and the like. These components are explained below.

[a) polyether polyol]
Component a) used in the present invention is one or more polyether polyols having an average number of hydroxyl groups of 2 to 4, oxypropylene repeating units, and a number average molecular weight of 1,000 to 6,000. Such polyols can be used for general flexible urethane foams such as flexible slab foams. Water or a polyhydric alcohol having an average of 2 to 4 hydroxyl groups in one molecule is used as a starting material, and an alkylene oxide is added to them. is produced by addition polymerization. Diethylene glycol; Propylene glycol; Dipropylene glycol; Butylene glycol; Pentanediol; Hexanediol; Neopentyl glycol; Glycerin; ethylene diamine; polyoxyalkylene polyols including alkylene oxide adducts such as aromatic diamines. Alkylene oxides used in the production of polyoxyalkylene polyols usually have 2 to 4 carbon atoms, and propylene oxide and mixtures of propylene oxide and ethylene oxide are preferred. These polyols may be used alone or in combination of two or more. For example, mixtures of bifunctional and tri- to tetra-functional substances and/or mixtures of substances with different molecular weights or different chemical compositions can be used. From the viewpoint of imparting low emission properties to the polyurethane foam, it is important to select non-volatile, high-molecular-weight additives (such as antioxidants and stabilizers) contained in the polyol.

Specific examples of polyether polyols useful as component a) include Voranol-3010, Voranol 3137, V230-056 Polyol (Dow Chemical Company), ARCOL Polyol 16-56, ARCOL 200 Polyol 16-56 (Arco Chimecal Co.) , NIAX Polyol 16-56 (AC West Virginia Polyol Company), Desmophen PU20WB01, Desmophen 7186, Desmophen VPPU 20 WB 01 (BAYER), polypropylene glycol-based polyether polyol No. 33 (Sanyo Chemical Industries, Ltd.), an EO/PO triol with a molecular weight of 3,500 containing 10% internal EO, glycerin as a starting material, EO/PO = 16/84 (weight ratio) addition-polymerized poly with a hydroxyl value of 56 Ether polyol, polyoxyalkylene triol {EO/PO=12/88 (weight ratio), hydroxyl value 48}, glycerin as a starting material, hydroxyl value 46 obtained by addition polymerization at EO/PO=14/86 (weight ratio) A polyether polyol having a hydroxyl value of 46 obtained by addition polymerization of EO/PO=16/84 (weight ratio) using polyether polyol and glycerin as a starting material, and a PO/EO adduct of glycerin (hydroxy value of 33).

[a') polyol other than the above a)]
Preferred examples of polyols that can be used in combination with component a) in the present invention include halogenated polyether polyols and brominated polyols (dibromoneopentyl glycol, brominated pentaerythritol, epi polymerized polyols of chlorohydrins and brominated polyols). For the purpose of improving the curing reaction speed and adjusting the cell size, polyether polyols with relatively low molecular weight and high functionality: polyhydric alcohols with an average number of hydroxyl groups of 3 to 8 and a number average molecular weight of 250 to 1000 Alkylene oxide adducts to polyvalent amines are also preferred. saccharides such as sorbitol; sucrose; lactose; α-methylglucoside; α-hydroxyalkylglucoside; Adducts of ethylene oxide are mentioned.

In addition, carboxylic acids such as adipic acid and phthalic acid and polyhydric alcohols such as ethylene glycol, 1,4-butanediol and 1,6-hexanediol can be dehydrated and condensed as long as the effects of the present invention are not impaired. polyester polyols produced by HR foams, polyether polyols with a high content of primary hydroxyl groups and an average molecular weight of about 5000 to 7000, which are usually used for HR foams, and copolymerization of acrylonitrile, styrene, etc. in polyether polyols. A polymer polyol or the like in which fine polymer particles are dispersed by means of a polymer may be appropriately selected and used in combination.

[b) Polyisocyanate]
As the polyisocyanate, it is preferable to select a non-volatile or non-volatile organic polyisocyanate, especially in the case of on-site foaming, considering the safety of workers and the surrounding environment on the premise that it will be used for spraying.

As component b), commercially advantageous materials are MDI (diphenylmethane diisocyanate), 4,4'-diphenylmethane diisocyanate, 4,2'-diphenylmethane diisocyanate, polymeric MDI (polymethylene polyphenyl polyisocyanate), crude MDI. . In addition, as isocyanate group-containing prepolymers, MDI prepolymers prepared by reacting MDI with polyols, TDI prepolymers prepared by reacting TDI with polyols, and other aromatic or aliphatic polyisocyanates. Also usable are prepolymers prepared by the reaction of polyols with uretonimine-modified polyisocyanates and their prepolymers. As component b), a derivative of the above polyisocyanate may be selected.

From the viewpoint of imparting low emission properties to the polyurethane foam, it is preferable to select the nonvolatile or nonvolatile organic polyisocyanate as described above. On the other hand, when foam is sprayed into a mold such as a heat insulating panel in a factory and then heated and cured using automated work equipment, after ensuring the safety of the work environment such as a local exhaust system, the above non-volatile or non-volatile In some cases, toluene diisocyanate (TDI) can be used, as well as organic polyisocyanates. There are two types of TDI, 2,4 and 2,6 isomers, and a mixture of 2,4 isomers/2,6 isomers=80/20 is usually distributed, so this may be used. The amount of polyisocyanate incorporated relative to the amount of other ingredients in the formulation is expressed by the "isocyanate index." "Isocyanate Index" is the actual amount of polyisocyanate used divided by the stoichiometric amount of polyisocyanate required to react with all active hydrogens in the reaction mixture multiplied by 100. .

Since the polyurethane spray foam system according to the present invention uses a large amount of water, the preferred range of the isocyanate index in component b) is generally in the range of 30 to 80, unlike the range in general polyurethane foams.

From the point of view of the use of the foam booster in the present invention, the polyisocyanate is MDI (diphenylmethane diisocyanate), polymeric MDI (polymethylene polyphenyl polyisocyanate), crude MDI, isocyanate, in the applied water blown polyurethane spray foam system. a component selected from group-containing prepolymers and derivatives thereof, and the blowing agent (d)) of the same system is water as the main blowing agent, more preferably substantially only water, or other blowing agents Combinations containing no agents and only water are particularly preferred. In that case, the isocyanate index of component b) is preferably in the range of 20-80, more preferably 30-70.

[c) Urethane catalyst]
Metal catalysts and tertiary amines are generally used as catalysts for polyurethane resin production. and organic polyisocyanate to generate carbon dioxide gas, it is widely used in the formation of various types of urethane foam. On the other hand, metal catalysts, typified by tin catalysts, are mainly used in non-foaming urethane fields because they have high catalytic activity for promoting urethanization reactions and are excellent in practical use. In the formulation of , the tin-based catalyst is also used in combination with the amine-based catalyst. In addition, nickel-based catalysts are mainly used in the formulation of mechanical froth foam.

Since the polyurethane spray foam system according to the present invention uses a large amount of water, it generates more heat of reaction than general flexible foams, and therefore has a high reaction rate. Therefore, it is usually sufficient to use an amine-based catalyst. The amine-based catalyst may be used alone or in combination of two or more depending on the purpose of adjusting the reaction rate and foaming state. Examples of such amine-based catalysts include dimethylethanolamine, dimethylaminoethoxyethanol, triethylenediamine, bis(2-dimethylaminoethyl)ether, N,N,N',N'-tetramethylhexamethylenediamine, N ,N′,N′,N″-Pentamethyldiethylenetriamine and other tertiary amine urethane catalysts, imidazole derivatives, slow-acting tertiary amine catalysts, general type tertiary amine catalysts, low-emission tertiary amine catalysts, non-emission tertiary Examples include amine catalysts and DABCO (registered trademark) catalysts from Air Products.From the viewpoint of imparting low emission characteristics to polyurethane foams, it is preferable to use reactive amine catalysts.If necessary, metal catalysts are used in combination. Examples of these include nickel acetoacetonate, iron acetoacetonate, tin-based catalysts, bismuth-based catalysts, zinc-based catalysts, titanium-based catalysts, aluminum complexes, zirconium complexes, potassium octylate, potassium acetate. , sodium acetate, sodium octylate, metal oxide particles having solid acid points on the surface, quaternary ammonium carboxylic acid, etc. The amount of component c) added is usually 1 to 1 to 100 parts by weight of the total polyol. 5 parts by weight.

[d) blowing agent that is water]
The polyurethane spray foam system of the present invention produces a low density, lightweight, flexible urethane foam for insulation or sound absorption, typically expanded 100 times with water as the primary blowing agent (before foaming). If the density of the urethane mixed solution is assumed to be 1.0 g/cm3, the density of the foam after foaming is 0.01 g/cm3). Therefore, the number of parts of water added to 100 parts of the sum of polyether polyol and other polyol components as component a) in the system should be in the range of 10 to 40 parts, preferably in the range of 15 to 35 parts. within the range of 15 to 25 parts.

Purified water, pure water, distilled water, ion-exchanged water, tap water, tap water, and the like can be suitably used as water. In the case of on-site foaming spraying, the blowing agent is preferably substantially only water from the standpoint of convenience and cost. is particularly preferred. If another expensive foaming agent is used in combination, gas will escape due to the open cell structure of the foam. It may be wasted in terms of effectiveness. Therefore, component d) is preferably water in an amount of 95% by mass or more, more preferably 99% by mass or more, and still more preferably 99 to 100% by mass, from the viewpoints of convenience and cost. It is one of the commercial and technical advantages of the foam enhancer according to the present invention that water, which can be easily and inexpensively procured at construction sites or the like, can be used as it is as a foaming agent.

On the other hand, when the foam is sprayed into a mold such as a heat insulating panel in a factory and the process from spray injection to heat curing is performed by automated work equipment, flame-retardant foaming agents such as HFC-245fa and HFC-134a Hydrofluorocarbons , hydrofluoroolefins such as HFO and HCFO may be used in combination. If these expensive gases do not leak out of the filled mold with the foam, it helps improve insulation.

[f) nonionic surfactant]
Component f) is one of the optional constituents of the polyurethane spray foam system of the present invention, whose primary purpose is to stabilize the premix liquid for the polyurethane spray foam system of the present invention. The nonionic surfactant that is component f) is a nonionic organic surfactant or emulsifier that does not contain a silicon atom in its molecular structure. Polyether copolymers and foam enhancers containing them are excluded, and non-silicone surfactants or emulsifiers that do not have a silicon atom in their molecular structure (hereinafter referred to as "organic") are particularly preferred. be.

For the component f), addition of a nonionic organic surfactant capable of improving the clouding point of the system is effective in ensuring the storage stability of the premixed liquid over time and temperature. Component a) according to the present invention: polyether polyol and component d): high HLB (water-soluble) nonionic emulsifiers are preferable because they need to act as compatibilizers with water, such as POE nonylphenyl ether and POE octylphenyl Polyoxyethylene alkylphenyl ethers such as ethers, POE fatty alcohol ethers, POE synthetic alcohol ethers, POE branched alcohol ethers, POE secondary alcohol ethers and the like can be used. The number of added moles of oxyethylene can usually be in the high range of 2 to 100, but from the viewpoint of water solubility, it is preferably 7 moles or more, and from the viewpoint of availability and ease of handling, it is preferably 30 moles or less. Particularly preferred are POE(9-20) nonylphenyl ether and POE(9-20)octylphenyl ether. The preferred amount of component f) used is 5 to 30 parts by weight per 100 parts by weight of the total amount of polyol. If the amount is less than 5 parts, the polyols having different polarities cannot be made compatible with each other or the polyol and water cannot be made compatible, making it difficult to obtain a homogeneous premix solution. opening) is less likely to occur, and foam shrinkage is more likely to occur.

[g) flame retardant]
The g) component is one of the arbitrary configurations of the polyurethane spray foam system according to the above, and the flame retardant used in the present invention is a flame retardant component other than the flame retardant polyol included in a') above, such as Phosphate esters such as trimethyl phosphate, triethyl phosphate, trischloroethyl phosphate and trischloropropyl phosphate. The amount used is preferably 40 to 80 parts by weight per 100 parts by weight of the total polyol in a formulation that does not use a flame-retardant polyol. If it is less than 40 parts by weight, the flame retardant effect may be insufficient. On the other hand, if the amount exceeds 80 parts by weight, the compatibility of the polyol component becomes too high, which may make it difficult to form open cells. A particularly preferred amount is 50 to 70 parts by weight. On the other hand, in a formulation in which 15 to 35 parts by weight of the flame-retardant polyol is added to the total polyol (100 parts by weight), the amount of component g) used is preferably 20 to 40 parts by weight. The flame retardant g) can also be mixed with the polyisocyanate component to form the urethane foam. These flame retardants reduce the viscosity of the urethane mixture and facilitate uniform foam formation by spraying. They also act as plasticizers for the polyurethane resin, improving the adhesion of the foam to the substrate. contribute.

[h) optional component]
h) component is a foam stabilizer for urethane foam other than the foam enhancer according to the present invention, a diluent, a chain extender, a cross-linking agent, a secondary amount of a non-aqueous foaming agent, a cell opening agent, a filler, a reinforcing agents, pigments, dyes, colorants, antioxidants, antiozonants, UV stabilizers, antistatic agents, bactericides and antibacterial agents, etc., which are known in the art and optional, and which are technically useful in the present invention. They may be included within the range of their normal content as long as the effect is not impaired. From the viewpoint of imparting low emission characteristics, even if these optional ingredients, it is confirmed that the material is composed only of ingredients that do not cause release due to migration or volatilization from the foam, and the foam formulation is adjusted. Compounding is important in formulating polyurethane foam-forming compositions.

For example, as a foam stabilizer for urethane foam other than the foam enhancer according to the present invention, a general foam stabilizer for flexible slab foam may be used in combination within a range that does not impair the effects of the present invention. For example, L-520 (Si—O—C type silicone polyether copolymer) first commercialized by Union Carbide, and VORASURF DC198 Additive, DC5950 Additive, DC5943 Additive, DC5160 sold by Dow Chemical Company. Additive, DC5900 Additive, DC5933 Additive, DC5982 Additive, DC5986 Additive, DC5987 Additive, DC5990 Additive (Si-C type silicone polyether copolymer) and SRX28H280A, SRX9SRX9SRX9SRX9SRX9SRX4SRX sold by Dow Toray 190 (Si—C type silicone polyether copolymer). In addition, in the formulation using a polyether polyol with a relatively low molecular weight and high functionality as the above a'), from the viewpoint of adapting to a higher polarity system, an appropriate amount of hard It is also possible to use a silicone foam stabilizer for foam together. Furthermore, general silicone foam stabilizers for HR foams and silicone foam stabilizers for microcellular foams may act as cell-opening agents in the system according to the present invention. good.

The optional h) component crosslinker or chain extender may contain a polyhydroxyl terminated compound having 2 to 8 hydroxyl groups per molecule and a molecular weight of 62-500. Crosslinkers with 3 to 8 hydroxyl groups include glycerin, trimethylolpropane, pentaerythritol, mannitol, sorbitol, and the like. Examples of useful chain extenders with two hydroxyl groups are dipropylene glycol, tripropylene glycol, propylene glycol, diethylene glycol, triethylene glycol, 1,4-butanediol, ethylene glycol, 2,3-butanediol, 2-methyl-1,3-propanediol, 1,2-propanediol, 1,3-propanediol and neopentyl glycol and the like. Diethanolamine, monoethanolamine, and the like can also be used. These compounds may also be treated as diluents. Other suitable diluents include polyalkylene glycols or derivatives thereof that are liquid at 25°C.

The optional h) component may also contain fillers, such as inorganic fillers or combinations of fillers. Fillers may be used for density modification, improving physical performance such as mechanical performance or sound absorption, flame retardancy or other benefits including improved economics such as calcium carbonate. or other fillers that reduce the cost of foam production, aluminum hydroxide or other flame retardant fillers, barium sulfate or other high density fillers used for sound absorption, glass or other fillers that further reduce foam density Contains microspheres of polymer-like material. High aspect ratio fillers or reinforcing agents used to modify the mechanical performance of foams, such as rigid or flexible modules, include man-made fibers such as ground glass or graphite fibers; natural animal fibers such as wool or vegetable fibers such as cotton; artificial plate-like fibers such as ground glass; and natural mineral plate-like fillers such as mica. Including any pigments, dyes or colorants that may be added. Furthermore, the present invention includes anti-ozonants, antioxidants; heat or thermo-oxygen decomposition inhibitors, UV stabilizers, UV absorbers, or the resulting foam heat, light when added to the foam-forming composition. and/or use of any other additive that avoids or inhibits chemical degradation is contemplated. Also contemplated for use herein are any of the known and conventional antistatic agents, disinfectants, antibacterial agents and gas fade inhibitors.

[Premix liquid]
The premix liquid for the polyurethane spray foam system according to the present invention comprises: a) polyether polyol, c) urethane catalyst, d) water blowing agent: polyether polyol as component a) in said system and other It contains at least 10 to 40 parts by weight per 100 parts by weight of the total polyol components, and e) a foam enhancer having a hydrophobicity-enhancing effect containing the silicone polyether copolymer.

Furthermore, the premix liquid for the polyurethane spray foam system according to the present invention preferably further contains f) a nonionic surfactant, particularly an organic nonionic surfactant. Premix fluids for polyurethane spray foam systems according to the present invention may have a color derived from the substrate, but usually have the properties of clear homogeneous fluids.

[Composition for Forming Polyurethane Spray Foam]
The composition for forming a polyurethane spray foam according to the present invention comprises components a), b), c), d) and e), and optionally one selected from a′) and f) above. can contain one or more The composition also further comprises g) a flame retardant and optionally h) other additives. The types and amounts of each component are as described for the polyurethane spray foam system.

An example of the formulation of the polyurethane spray foam-forming composition according to the present invention is shown below. Here, the following component a) is "one type having an average number of hydroxyl groups in the molecule of 2 to 4, having a repeating unit composed of an oxypropylene group, and having a number average molecular weight within the range of 1000 to 6000. It satisfies the above polyether polyol requirements. Also, the concentration of the isocyanate groups in component b) below is 30.5 to 32.0 wt. % range.
Formula 1 :
a) Polypropylene glycol-based polyether polyol (Sanyo Kasei No. 33) 100 parts by weight c) DABCO 33LV (triethylenediamine, Sigma Aldrich) 2 parts by weight e) Foam enhancer or comparative foam stabilizer 1 part by weight d) Water 25 parts by weight g) Trischloropropyl phosphate (Daihachi Chemical, flame retardant TMCPP) 60 parts by weight b) Millionate MR-100 (Tosoh, Polymeric MDI) 207 parts by weight

The composition for forming polyurethane spray foam according to the present invention can be used particularly suitably for forming flexible polyurethane foams, and meets the current needs of the polyurethane industry, which requires strict VOC (volatile organic compound) control or emission control. It is possible. More specifically, the content of the low-molecular-weight siloxane having 20 or less silicon atoms in the foam enhancer can be easily suppressed to 5000 ppm (weight) or less, 2000 ppm (weight) or less, or 1000 ppm (weight) or less. Moreover, since the amount itself used as a foam enhancer is small, VOCs derived from these volatile siloxanes and their emissions can be almost completely suppressed in the finally obtained polyurethane foam. If the content of these components in the foam enhancer exceeds 5000 ppm, when the foam enhancer is used as a foam stabilizer for a polyurethane foam, the surrounding members around the place where the polyurethane foam is installed will be contaminated, It is not preferable because it may cause contact failure of electric/electronic devices.

The flexible polyurethane foam obtained by curing the composition for forming polyurethane spray foam according to the present invention is not limited in its use, but is a building material cured by on-site foaming, in particular, a heat insulating material or a sound absorbing material. It can be suitably used as

The flexible polyurethane foam according to the present invention has a stable premixed liquid, excellent handling workability, and excellent foaming properties, and can be used at a building manufacturing site even if it is used in a small amount. (= foam volume), it is excellent in terms of cost and work efficiency in building applications, etc. The resulting foam has a fine cell structure and is suitable for applications such as heat insulation / sound absorption Moreover, compared with the use of conventional foam enhancers, the hydrophobicity of polyurethane foams (especially flexible polyurethane foams) can be significantly improved, which is a major advantage not found in the prior art, and In recent years, it can satisfy the requirements of Low Emission/Low VOC, which are of high importance especially in building applications.

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these. The number average molecular weight other than the "formula weight" is a value obtained as a polystyrene equivalent by GPC (detector: refractometer) using a chloroform eluent.

Hereinafter, the performance evaluation procedure of the foam enhancer according to the present invention is A: Premix compatibility test, B: Formation of urethane foam, C: Evaluation of volume / cell structure of urethane foam, D: Water absorption test of urethane foam I will explain in order.

[A: Premix compatibility test]
For the foam enhancer of the present invention and the foam stabilizer for comparison, a compatibility test in a premix liquid was conducted according to the following procedure.
A 1. Charge 50 g of a) polyether polyol and proportions of d) water, c) urethane catalyst, e) foam enhancer or comparative foam stabilizer to a 100 mL glass bottle.
A2. Homogenize the contents by stirring for 1 minute using a disk-shaped disper mixer with a saw blade.
A3. Cap the vial and let stand overnight at room temperature to allow bubbles to dissipate.
A4. Visually check the appearance (transparency) of the mixture and record it.

[B: Formation of urethane foam]
B1. The premix liquid prepared in A above, g) flame retardant, and b) polyisocyanate were charged in a predetermined ratio such that the total weight was 20 g in a 200 mL plastic cup, and immediately, a disk-shaped disper mixer with a saw blade was added to the mixture at 3500 rpm. , stirring for 7 seconds.
B2. The agitation of the mixer is stopped and immediately the resulting homogeneously mixed polyurethane spray foaming composition is poured into a 1 L plastic cup and allowed to foam naturally. The time from the start of pouring to the end is fixed at 8 seconds.
B3. The resulting foam is allowed to stand overnight at room temperature.

[C: Evaluation of Urethane Foam Volume/Cell Structure]
C1. Cut the foam containing the plastic cup prepared in B above into upper and lower halves using an electric cutter.
C2. The height of the foam (in mm) and the homogeneity of the cell structure of the cross section of the foam are recorded.

[D: Water absorption test of urethane foam]
D1. The foam pieces obtained in C above are further chopped with an electric cutter to prepare rectangular parallelepiped test pieces of length 6.5 cm x width 6.5 cm x height 4 cm. Here, it is assumed that this test piece was sampled from the center of the foam containing the plastic cup prepared in B above.
D2. Measure and record the weight of the test piece.
D3. Prepare a water bath.
D4. The bottom half of the test piece is immersed in the water bath for 2 hours, then removed and weighed and recorded.
D5. Calculate and record the water absorption (% by weight) of the test piece.

In the first round of testing, a comparison was made between the following two groups as comparative foam stabilizers. These consist primarily of commercially available foam stabilizers. In addition, in the composition formula representing the silicone polyether copolymer which is the main component of these foam stabilizers, the Me ₃ SiO group (or Me ₃ Si group) is “M ”, the Me ₂ SiO group is “D ”, A Me ₂ HSiO group is denoted as “M ^H ”, a MeHSiO group is denoted as “D ^H ”, and a unit obtained by modifying one of the methyl groups in M and D with some substituent (modifying group * or **) is It is written as M ^* , D ^* , and so on. (EO) represents an oxyethylene group, (PO) represents an oxypropylene group, Me represents a methyl group, and Ac represents an acetyl group.
[Comparative foam stabilizer (first round)]
・Group R: 9 foam stabilizers for rigid urethane foam ・Group F: 3 foam stabilizers for flexible slab foam

The identification numbers of the comparative foam stabilizers belonging to Group R and the average compositional formula of the main components are shown below. Although (EO) and (PO) are expressed in a block-bonded form for simplicity, it is actually a random addition structure.
Comparative foam stabilizer _R1 : M ^* _D25D ^* 1M ^* , ^* =- _C3H6O (EO) ₁₅ (PO) ₅ _- H
Comparative foam stabilizer R2: MD ₄₃ D ^* _6.8 M, ^* = -C ₃ H ₆ O(EO) ₂₆ (PO) ₆ -CH ₃
Comparative foam stabilizer R3: MD ₅₀ D ^* ₇ M, ^* = -C ₃ H ₆ O(EO) ₁₁ (PO) _3.5 -H
Comparative foam stabilizer R4: M ^* _D18D ^* 3M ^* _, ^* =-C3H6O(EO) ₁₅ ₍ PO) ₅ _- _CH3
Comparative foam stabilizer R5: M ^* _D25 D ^* ₁ M ^* , ^* =-C3H6O ₍ EO) ₂₄ (PO) ₆ _- _CH3
Comparative foam stabilizer R6: MD ₃₄ D ^* _5.7 M, ^* = -C ₃ H ₆ O(EO) ₁₂ (PO) ₂ -H
Comparative foam stabilizer R7: MD ₃₄ D ^* _5.7 M, ^* = -C ₃ H ₆ O(EO) ₁₁ (PO) _3.5 -H
Comparative foam stabilizer R8: M ^* _D42 D ^* ₅ M ^* , ^* =-C3H6O ₍ EO) ₁₇ (PO) ₇ _- _CH3
Comparative foam stabilizer R9: MD ₃₇ D ^* _3.4 D ^** _2.1 M, ^* = - C ₃ H ₆ O(EO) ₁₁ (PO) _3.5 - CH ₃ , ^** = - C ₃ H ₆ O(EO) ₁₁ (PO) _3.5 -H

The identification numbers of the comparative foam stabilizers belonging to Group F and the average compositional formula of the main components are shown below. Although (EO) and (PO) are expressed in a block-bonded form for simplicity, it is actually a random addition structure.
Comparative foam stabilizer F1: MD ₅₀ D ^* _5.9 M, ^* = -C ₃ H ₆ O(EO) ₂₂ (PO) ₂₂ -CH ₃
Comparative foam stabilizer F2: MD ₃₃ D ^* _2.8 M, ^* = -C ₃ H ₆ O(EO) ₂₂ (PO) ₂₂ -CH ₃
Comparative foam stabilizer F3: MD ₅₃ D ^* ₃ M, ^* = -C ₃ H ₆ O(EO) ₂₂ (PO) ₂₂ -COCH ₃

The structural elements of the 12 foam stabilizers for comparison are summarized below.
[Table 1]: Structure of comparative foam stabilizer (first round)

The performance evaluation results of the 12 foam stabilizers for comparison are summarized below. Data not collected or not recorded are indicated with "-".
[Table 2]: Relationship between performance and structure of comparative foam stabilizers (first round)

From the above results, when the polyether terminal group Y of the silicone foam stabilizer has a structure mainly composed of H, the compatibility with the premix liquid is insufficient, and it tends to be difficult to obtain a transparent appearance. Do you get it. In addition, all foams with excellent foam height (volume) had a transparent appearance of the premix liquid, indicating that structural design with excellent premix compatibility is important. Next, regarding the water absorption rate of the foam, it was found that generally lower values were obtained when using the foam stabilizer for soft slabs (Group F) than when using the foam stabilizer for rigid foams (Group R). Do you get it.

However, there is a demand for a foam with a low water absorption rate while obtaining the same level of foam volume as when using the foam stabilizer for soft slabs. Therefore, 12 silicone polyether copolymers with different structures were newly synthesized, and their performance was evaluated by comparing them with the above R8 and F3. Details are as follows.

[Synthesis of copolymer for example/comparative example (second round)]
For reference, the synthesis procedure for one silicone polyether copolymer (foam enhancer of the present invention) of the example is shown below. Other example samples and comparative example samples (comparative foam stabilizers) differed in the structure or combination of the organohydrogenpolysiloxane and the one-end allyl group-containing polyether, which are the main raw materials, but were generally the same as in this example. synthesized according to the procedure. In the composition formulas representing these silicone polyether copolymers, the Me ₃ SiO group (or Me ₃ Si group) is "M", the Me ₂ SiO group is "D", and the Me ₂ HSiO group is "M ^H , a MeHSiO group is denoted as “D ^H ”, and units obtained by modifying one of the methyl groups in M and D with some substituent (* or **) are denoted as M ^* and D ^* , and the like. (EO) represents an oxyethylene group, (PO) represents an oxypropylene group, Me represents a methyl group, and Ac represents an acetyl group.

<Example 1> Production of foam enhancer with identification number SI-1 An organohydrogen represented by the average composition formula MD ₅₃ D ^H ₃ M and having a concentration analysis value of hydrogen groups bonded to silicon atoms of 0.072% by mass. 139.68 g of genpolysiloxane raw material, represented by the average compositional formula CH ₂ ═CH—CH ₂ —O(C ₂ H ₄ O) ₉ (C ₃ H ₆ O) ₂₂ —H, concentration analysis value of unsaturated groups is 0.45 mmol/g and the hydroxyl value analysis value is 28.4 mg-KOH/g. Heating was started while setting the temperature of the oil bath to 85°C. The allyl/SiH molar ratio in this reaction system was 1.4. At a temperature of 45 to 50 ° C. to the contents of the flask, 244 ppm of an IPA solution (Pt concentration 0.4 wt%) of a platinum-divinyldisiloxane complex (Karlstadt catalyst) (equivalent to 10 ppm as platinum) was added, and after 18 minutes, the reaction liquid has become transparent. The reaction was carried out for 80 minutes while maintaining the temperature of the liquid in the flask at 80°C. Next, 1 g of the reaction solution was sampled and confirmed by the alkali decomposition gas generation method, and the reaction was completed. The temperature of the oil bath was set to 125° C., the nitrogen flow rate was increased, and distillation of IPA was started under normal pressure. When the distillation rate slowed down, the IPA in the receiver was temporarily discarded, and the pressure in the system was gradually reduced to 30 mmHg while paying attention to bubbling and bumping. After that, the temperature of the liquid in the flask was maintained at 110 to 125° C. and the pressure was kept at 10 mmHg or less for 75 minutes to remove volatile matter. After that, the heating was stopped, the flask was allowed to cool to 95°C or less, and the pressure was restored.

As a result, a silicone polyether copolymer represented by the average composition formula MD ₅₃ D ^* ₃ M { ^* = -C ₃ H ₆ O(C ₂ H ₄ O) ₉ (C ₃ H ₆ O) ₂₂ -H} A pale yellowish brown transparent homogeneous liquid containing It should be noted that although the polyoxyethylene group and the polyoxypropylene group are expressed in a form of block bonding for the sake of simplicity, it is actually a random addition structure.
Foam booster SI-1: MD ₅₃ D ^* ₃ M, ^* = -C ₃ H ₆ O(EO) ₉ (PO) ₂₂ -H

<Examples 2 to 4> Structures of foam enhancers with identification numbers SI-2 to SI-4 Below are shown the identification numbers of the example samples and the average compositional formula of the main components. Although (EO) and (PO) are expressed in a block-bonded form for simplicity, it is actually a random addition structure.
Foam booster SI-2: MD ₅₃ D ^* ₃ M, ^* = -C ₃ H ₆ O(EO) ₁₈ (PO) ₁₆ -H
Foam booster SI-3: MD ₅₄ D ^* _6.5 M, ^* = - C ₃ H ₆ O(EO) ₁₈ (PO) ₁₆ -H
Foam booster SI-4: MD ₈₃ D ^* _7.7 M, ^* = - C ₃ H ₆ O(EO) ₁₈ (PO) ₁₆ -H

<Comparative Examples 1 to 8> Identification numbers SR-1 to SR-8
The identification numbers of the comparative samples and the average compositional formula of the main components are shown below. Although (EO) and (PO) are expressed in a block-bonded form for simplicity, it is actually a random addition structure.
Comparative foam stabilizer SR-1: MD ₅₃ D ^* ₃ M, ^* = -C ₃ H ₆ O (EO) ₃₀ (PO) ₁₀ -H
Comparative foam stabilizer SR-2: MD ₅₄ D ^* _6.5 M, ^* = -C ₃ H ₆ O(EO) ₁₅ (PO) ₅ -H
Comparative foam stabilizer SR-3: MD ₅₄ D ^* _6.5 M, ^* = -C ₃ H ₆ O(EO) ₂₁ (PO) ₉ -H
Comparative foam stabilizer SR-4: MD ₅₄ D ^* _6.5 M, ^* = -C ₃ H ₆ O(EO) ₃₀ (PO) ₁₀ -H
Comparative foam stabilizer SR-5: MD ₈₃ D ^* _7.7 M, ^* = -C ₃ H ₆ O(EO) ₂₁ (PO) ₉ -H
Comparative foam stabilizer SR-6: MD ₈₃ D ^* _7.7 M, ^* = -C ₃ H ₆ O(EO) ₃₀ (PO) ₁₀ -H
Comparative foam stabilizer SR-7: MD ₅₄ D ^* _6.5 M, ^* = -C ₃ H ₆ O(EO) ₂₁ (PO) ₉ -CH ₃
Comparative foam stabilizer SR-8: MD ₈₃ D ^* _7.7 M, ^* = -C ₃ H ₆ O(EO) ₂₁ (PO) ₉ -CH ₃

The structural elements of the 12 example/comparative copolymer samples are summarized below. For comparison, R8 and F3 are also included in the display.
[Table 3]: Structure of prototype sample (second round)

The performance evaluation results of 12 copolymer samples for Examples/Comparative Examples are summarized below. Data not collected or not recorded are indicated with "-". For comparison, R8 and F3 are also included in the display.
[Table 4]: Relationship between performance and structure of prototype samples (second round)

From the above results, even if the polyether terminal group Y of the silicone foam stabilizer has a structure mainly composed of H, when the value of the ratio Z is large (here, it has a PO-rich long polyether chain) It has been found that the foam has excellent compatibility with the premix system, has a large volume, has a good cell structure, and has a low water absorption rate. That is, it was found that the hydrophobicity of the urethane foam itself can be improved by selecting the specific chemical structure of the silicone polyether copolymer used as a foam stabilizer for urethane foam. On the other hand, when the polyether terminal group Y of the silicone foam stabilizer has a capped structure such as Me or Ac, it is characterized by excellent compatibility with the premix even if the value of the ratio Z is small. It is clear that the foam has a high water absorption rate and cannot meet the market needs.

In particular, the foam enhancers SI-1 to SI-4 of the present invention do not require capping of the hydroxyl group portion of the single-ended allyl polyether, which is the raw material, and therefore the soft slabs currently being diverted to spray foam systems It has the advantage of being cheaper to manufacture than foam stabilizers. Nevertheless, as shown in Table 4 above, it outperforms F3 in terms of overall performance balance. Therefore, the foam enhancer of the present invention greatly contributes to the sound development of society and industry.

[Confirmation of Low Emission Properties]
The foam enhancers SI-1 to SI-3 of the present invention were analyzed for volatile cyclic siloxanes (D4 to D6) by the headspace GC method according to the following procedure.
E1. About 1 g of sample was weighed into a 20 mL vial and sealed.
E2. After heating the vial at 150° C. for 30 minutes, 1 mL of headspace was injected into GC using a headspace sampler and measured.

The analysis results in the above GC are summarized in Table 5 below. Each component of the cyclic siloxane was well below 0.10% (1000 ppm), and it was confirmed that there was no problem from the viewpoint of Low Emission.
Table 5: Volatile siloxane content of foam boosters of the invention (unit: wt.ppm)

The following is a formulation example of a composition for forming a 100 times water expanded polyurethane thermal insulation spray foam suitable for use with the foam enhancer of the present invention.
[Table 6]: Composition for forming flexible polyurethane thermal insulation spray foam (100-fold expansion with water)
In addition, component a) in the table below is "one type having an average number of hydroxyl groups in the molecule of 2 to 4, having a repeating unit consisting of an oxypropylene group, and having a number average molecular weight within the range of 1000 to 6000. It satisfies the above polyether polyol requirements. Also, the calculated isocyanate index for Formulation 2 and Formulation 3 in the table below is about 30.

Claims

General formula (1):

{wherein each R independently represents a monovalent hydrocarbon group having 1 to 16 carbon atoms selected from alkyl, aryl and aralkyl groups,
Each X is independently one or more of the formula: -C k H 2k O-(C 2 H 4 O) p (C 3 H 6 O) q (C 4 H 8 O) r -Y represents the polyether group of
Y is 100 mol % of H groups, or consists of 75 mol % or more of H groups and 25 mol % or less of other groups selected from C1-C4 alkyl or acetyl groups;
m, n, k, p, q, and r are numbers satisfying the following conditions.
12≦(m+n)≦230,
10≦m,
2≦n,
n≦m,
3≤k≤4,
p, q, and r have a formula weight of the polyether group moiety represented by X in the range of 1400 to 4000,
{sum of the formula weights of the oxypropylene group moiety represented by ( C3H6O )q and the oxybutylene group moiety represented by ( C4H8O )r}/ { ( C2H4O )p The sum of the formula weights of the oxyethylene group moieties represented by)} is the ratio value Z,
It is a number that satisfies the condition (51/49)≤Z≤(95/5).
However, in X in the formula, a polyether group having a structure where 1≤p and q=r=0 is excluded. }
A foam booster containing a silicone polyether copolymer of the formula for application in water-blown polyurethane spray foam systems comprising the following components a)-d):
a) one or more polyether polyols having an average number of hydroxyl groups in the molecule of 2 to 4, having repeating units composed of oxypropylene groups, and having a number average molecular weight in the range of 1,000 to 6,000;
b) polyisocyanates,
c) a curing catalyst,
d) Blowing agent, which is water: 10 to 40 parts by mass per 100 parts by mass of the sum of polyether polyol and other polyol components, which is component a) in the same system.
In the general formula (1),
each X independently of the formula: -C 3 H 6 O(C 2 H 4 O) p (C 3 H 6 O) q -H
One or two or more polyether groups represented by
The formula weight of the polyether group portion represented by X is in the range of 1500 to 2500, and
The ratio Z satisfies the condition of (54/46)≤Z≤(80/20),
2. The foam enhancer of claim 1.
In the general formula (1), R is a methyl group, m and n satisfy the conditions of 40 ≤ m ≤ 90 and 2 ≤ n ≤ 8,
3. The foam enhancer according to claim 1 or claim 2.
In said water-blown polyurethane spray foam system,
b) the polyisocyanate is a component selected from MDI (diphenylmethane diisocyanate), polymeric MDI (polymethylene polyphenyl polyisocyanate), crude MDI, isocyanate group-containing prepolymers, and derivatives thereof, and
characterized in that the blowing agent in the system is d) water only,
The foam enhancer according to any one of claims 1-3.
A premix fluid for a polyurethane spray foam system comprising components a)-d) above and e) a foam booster according to any one of claims 1-4.
6. The premix liquid for a polyurethane spray foam system according to claim 5, further comprising at least one or more polyol components other than the polyether polyol as component a').
f) The premix liquid for a polyurethane spray foam system according to claim 6, further containing a nonionic surfactant.
components a) to d) above, and e) a foam booster according to any one of claims 1 to 4, optionally one or more selected from components a') and component f) above. A composition for forming a polyurethane foam, further comprising:
9. The polyurethane foam-forming composition of Claim 8, further comprising g) a flame retardant and optionally h) other additives.
A flexible polyurethane foam obtained by curing the composition for forming a polyurethane foam according to claim 8 or 9.
11. The flexible polyurethane foam according to claim 10, having Low Emission/Low VOC properties.
A heat insulating or sound absorbing material comprising the flexible polyurethane foam according to claim 10 or claim 11.
General formula (1):

{wherein each R independently represents a monovalent hydrocarbon group having 1 to 16 carbon atoms selected from alkyl, aryl and aralkyl groups,
Each X is independently one or more of the formula: -C k H 2k O-(C 2 H 4 O) p (C 3 H 6 O) q (C 4 H 8 O) r -Y represents the polyether group of
Y is 100 mol % of H groups, or consists of 75 mol % or more of H groups and 25 mol % or less of other groups selected from C1-C4 alkyl or acetyl groups;
m, n, k, p, q, and r are numbers satisfying the following conditions.
12≦(m+n)≦230,
10≦m,
2≦n,
n≦m,
3≤k≤4,
p, q, and r have a formula weight of the polyether group moiety represented by X in the range of 1400 to 4000,
{sum of the formula weights of the oxypropylene group moiety represented by ( C3H6O )q and the oxybutylene group moiety represented by ( C4H8O )r}/ { ( C2H4O )p The sum of the formula weights of the oxyethylene group moieties represented by)} is the ratio value Z,
It is a number that satisfies the condition (51/49)≤Z≤(95/5).
However, in X in the formula, a polyether group having a structure where 1≤p and q=r=0 is excluded. }
A method for improving the hydrophobicity of a polyurethane foam, characterized by using a foam booster containing a silicone polyether copolymer represented by: