JPH0249060A - Polyurethane composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition capable of stably dispersing a large amount of water in fine particles and forming a dense polyurethane resin layer having an air-permeable cellular structure by blending a polyurethane with a specific surfactant consisting of a polyalkylene oxide-modified polysiloxane. CONSTITUTION:A polyurethane composition, consisting of an organic solvent (e.g., methyl ethyl ketone) having 1-50g/100g organic solvent solubility of water therein, a polyurethane resin and a surfactant consisting of a polyalkylene oxide-modified polysiloxane prepared by adding a polyalkylene oxide component to a polysiloxane at 20-80% weight ratio of polyethylene oxide chains in the polyalkylene oxide component and obtained by blending the surfactant in an amount of 0.1-15wt.% based on the polyurethane resin therewith.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a polyurethane composition used to form a breathable porous polyurethane resin layer.

[Conventional technology]

The organic solvent composition of the polyurethane resin, that is, the organic solvent solution of the polyurethane resin, and the polyurethane resin and the polyurethane resin in an amount of not more than 20% by weight of polyvinyl acetate, polyvinyl chloride,
An organic solvent solution of a polymer such as polyacrylic acid ester, polyamide, polyester, etc., or a coloring agent,
A water-in-oil type hydrous polyurethane dispersion is made by mixing and dispersing water with the help of a surfactant in a composition containing additives such as antistatic agents, light and heat stabilizers, etc. It is used to form a breathable porous polyurethane resin layer, etc. by first evaporating the organic solvent and then evaporating the water after soaking or impregnating it. In general, such water-in-oil polyurethane dispersions are left for a little longer after they are prepared (if this happens, the dispersed water particles may aggregate, become coarse, and become unevenly distributed, and the water particles may become coarse and unevenly distributed on the surface). There is a problem that a film is easily formed.

However, when the surfactant previously invented by the present inventors and known from Japanese Patent Publication No. 57-27232 is used as a surfactant, the surfactant improves the flexibility, antistatic properties, and stains of artificial leather. Although the purpose is to improve the prevention property, it is possible to obtain a relatively stable water-in-oil polyurethane dispersion.

[Problem to be solved by the invention]

The water-in-oil polyurethane dispersion using a surfactant described in Japanese Patent Publication No. 57-27232 also tends to form a film on the surface if left in a closed or open atmosphere at a relatively high temperature for a long time. There is a problem that the dispersed particles of water become coarse and unevenly distributed. Additionally, if you attempt to solve this problem by increasing the amount of surfactant used, the mechanical properties of the polyurethane resin formed will be markedly deteriorated, and the surfactant will easily ooze out onto the surface of the polyurethane resin layer, etc. Problems such as this will occur.

The present invention was made in order to solve the above-mentioned problems, and the mechanical properties of the polyurethane resin formed may be deteriorated, and the surfactant may easily ooze out on the surface of the polyurethane resin layer, etc. By using a surfactant, a relatively large amount of water can be dispersed into fine particles without causing a film to form on the surface or the dispersed water particles becoming coarse even if left for a long time under rough conditions. The purpose of the present invention is to provide a polyurethane composition capable of forming a water-in-oil polyurethane dispersion that is easy to store and does not become unevenly distributed.

[Means to solve the problem]

As a result of repeated research on surfactants that can stably disperse a large amount of water in the form of fine particles, the present inventors found that an interface made of polyalkylene oxide-modified polysiloxane in which a polyalkylene oxide component is added to a polysiloxane component. The surfactant has a weight ratio of polyethylene oxide chains to surfactant in the polyalkylene oxide component of 2.
It has been found that the desired polyurethane composition can be obtained when 0 to 80% of surfactant is used in the polyurethane composition.

The present invention was made based on this knowledge, and is a hydrated product in which water is mixed and dispersed by adding water to an organic solvent composition of an organic solvent and a polyurethane resin having a water solubility of 1 to 50 g/100 g of organic solvent. In a polyurethane composition capable of forming a polyurethane dispersion, a surfactant comprising a polyalkylene oxide-modified polysiloxane in which a polyalkyl oxide component is added to a polysiloxane component, and the surface activity of the polyethylene oxide chain in the polyalkylene oxide component The surfactant has a weight ratio of 20 to 80% based on the weight of the polyurethane resin, and contains a surfactant in a proportion of 0.1 to 15% by weight of the polyurethane resin, and the maximum critical water addition amount at which gelation occurs when water is added is 90%. % or less of water to form a stable water-containing polyurethane dispersion.

[For production]

The polyurethane composition of the present invention can disperse a relatively large amount of water as fine particles due to the above-mentioned structure, and the formed water-containing polyurethane dispersion is stable, and by using the dispersion, dense air permeability can be achieved. It is possible to stably form a polyurethane resin layer, etc. with a porous structure with excellent mechanical properties, and it provides the effect that surfactant does not ooze out on the surface of the formed polyurethane resin layer, etc. .

〔Example〕

Examples of the polyurethane resin in the present invention include polyalkylene ether diols such as polyethylene ether glycol, polypropylene ether glycol, and polytetramethylene ether glycol having a molecular weight of 1000 to 4000, and polyethylene adipate and polybutylene adipate having a molecular weight of too much to 4000.

Polyester diol such as polyhexamethylene adibate is used as a long chain diol, and diphenylmethane-4,4'-
Diisocyanate, tolylene-2,4-diisocyanate, phenylene diisocyanate, xylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, etc. are used as diisocyanate, and ethylene glycol, 1,4-butanediol, cyclohexane-1,4 -Diol.

α・α′-p-xylene diol, 1,4-bis(β-
hydroxyethoxy)benzene, 2,2-bis(4-(
Known polyurethane resins obtained by melt polymerization, solution or slurry polymerization using β-hydroxyethoxy)phenyl]propane, propylene diamine, hexamethylene diamine, etc. as a low molecular weight chain extender can be used. The organic solvent for solution or slurry polymerization preferably has a water solubility of 1 to 50 g/20° C. per 100 g of organic solvent, specifically methyl ethyl ketone and diethyl ketone.

Methyl propyl ketone, methyl isobutyl ketone.

Ethyl formate, propyl formate, butyl formate, methyl acetate,
Adjust the solubility of water to the above range by mixing ethyl acetate or the like with an organic solvent that is miscible with water such as tetrahydrofuran, acetone, or oxane, and an organic solvent that is immiscible with water such as benzene, toluene, xylene, etc. etc. are used.

The organic solvent composition for the polyurethane resin includes, in addition to the polyurethane resin, as long as it does not impair the physical properties of the polyurethane resin.
The polyurethane resin may contain a polymer such as polyvinyl acetate, polyvinyl chloride, polyacrylic acid ester, polyamide, polyester, etc. in an amount of 20% or less of the weight of the polyurethane resin, and may also contain a coloring agent, an antistatic agent, a flame retardant, a heat resistant agent, etc. Additives such as light stabilizers may be added as organic solvents for this composition, including organic solvents for slurry polymerization that have a boiling point of 12
0°C or lower, especially 100°C or lower is preferably used,
When the composition also contains a polymer other than polyurethane resin, a material that can also dissolve the polymer is used. Therefore, in the case of slurry-polymerized polyurethane resins, the composition may be prepared using the polymerization slurry without dispensing the polyurethane resin. It is preferable that the concentration including this is 5 to 30% by weight in order to obtain a water-in-oil polyurethane dispersion that is widely used for coating, impregnation, etc.

The surfactant can be obtained by addition-reacting alkylene oxide to polysiloxane by a known method, or by adding polyoxyalkylene glycol to a polysiloxane component having active groups such as hydroxyl groups or amino groups at the terminal or side chain with polyvalent isocyanate, etc. It consists of a combination of a hydrophobic component consisting of a polysiloxane component and a component of polyoxyalkylene oxide excluding polyethylene oxide, and a hydrophilic component consisting of polyethylene oxide in polyoxyalkylene oxide. If the weight ratio of the polyethylene oxide chains in the polyalkylene oxide component to the surfactant in this surfactant is less than 20%, it is thought to be caused by a lack of hydrophilic groups, but when the water-containing polyurethane dispersion is formed, When the stability of dispersion decreases and the storage temperature of the water-containing polyurethane/tan dispersion increases, association and uneven distribution of water-dispersed particles tend to occur. If you raise the temperature to evaporate enough water, the porous material will easily collapse. Furthermore, the molecular weight of the polysiloxane component and polyoxyalkylene oxide component, which are the hydrophobic components of the surfactant, is preferably 740 or more, and if it is less than 740, the surfactant tends to ooze out from the surface after forming the polyurethane resin layer, etc. Become.

The molecular weight of the surfactant is 1200 or more, especially 200.
0 or more and 12,000 or less, or a polysiloxane component obtained by bonding a polysiloxane component and a polyalkylene oxide component by a method using a diisocyanate as described in Japanese Patent Publication No. 57-27232, and a polysiloxane component and a polyalkylene oxide component. Preferably, the alkylene oxide component or even polyalkylene oxide components are bonded to each other by urethane or urea bonds, since the molecular weight of the surfactant has a similar effect to the molecular weight of the polysiloxane component, and This is because if the surfactant is formed by a urethane bond or a urea bond, the affinity with the polyurethane resin will be high, and the tendency for the surfactant to ooze out from the formed polyurethane resin layer etc. will be reduced.

If the amount of surfactant added is less than 0.1% by weight of the polyurethane resin, water may not be dispersed finely or the dispersion may become unstable, resulting in polyurethane with a fine porous structure. If the amount exceeds 15% by weight, it becomes impossible to obtain a water-containing polyurethane dispersion that can stably form a resin layer, etc.
Water may not be easily evaporated from the formed polyurethane resin layer, or the mechanical properties of the polyurethane resin layer may deteriorate.

The optimum amount of water for dispersing the surfactant-added polyurethane resin into the organic solvent composition varies depending on the concentration of the polyurethane resin, the amount of surfactant added, etc. The amount of critical water added is 90% or less, preferably 50 to 90%. If the amount of water added exceeds 90% of the maximum critical water addition amount, coarse water-dispersed particles may become mixed, or the polyurethane resin may gel, resulting in a densely structured breathable porous polyurethane. It may become impossible to form a resin layer, etc., or the mechanical properties of the polyurethane resin layer, etc. may deteriorate.

Hereinafter, further specific examples and comparative examples of the present invention will be shown.

Example 1 (1) to (4) 1) Polymerized polytetramethylene glycol (molecular weight 2190) of polyurethane slurry 30
0 parts, polycaprolactone diol (molecular weight 1810)
296 parts of diethylene glycol, 30 parts of diethylene glycol, and 315 parts of diphenyl 4,4' diisocyanate were dissolved in 235 parts of methyl ethyl ketone, and 0.2 parts of triethylene diamine was added and reacted at 60°C for 90 minutes, and the mixture ratio of methyl ethyl ketone/toluene was 9. Add 710 parts of a mixed solvent of /1,
Next, 60 parts of tetramethylene glycol was further added and stirred while controlling the temperature at 65 to 70°C, and as the viscosity increased, the methyl ethyl ketone/toluene mixing ratio was 9/9.
By pouring the mixed solvent of No. 1 and reacting for about 4 hours, the viscosity was 1800 cps/70°C. Polyurethane 20% by weight
A polyurethane slurry (A) was obtained.

2) Synthesis of polyalkylene oxide-modified polysiloxane Polypropylene oxide (PPO
) was subjected to an addition reaction under a caustic alkali catalyst, and then polyethylene oxide (PEO) was further subjected to an addition reaction to synthesize the surfactants shown in Table 1.

3) Preparation and storage of water-containing polyurethane dispersion Table 1 for each 100 parts of the aforementioned polyurethane slurry (A)
After adding the surfactant in the proportions shown, a -10 type aqueous dispersion was prepared by adding water little by little to 28 parts per 100 parts of slurry (A) while stirring with a homomixer. Pour the obtained dispersion into a sealed Erlenmeyer flask 4
The size of the water-dispersed particles in the W10 type aqueous dispersion was measured using a light transmission optical microscope after 3 hours after being immersed and stored in a constant temperature bath controlled at 0°C. The results are shown in Table 1. .

4) After adjusting the structure of the porous sheet and coating the modified Type 0 aqueous dispersion, which had been stored at 40°C for 3 hours, on a nylon film with a layer of approximately 30 g/m'', it was heated at 60°C and relative humidity of 40%. After drying for 5 minutes, it was dried at 100°C for 5 minutes.

Moisture permeability of the obtained polyurethane resin sheet.

Table 1 shows the characteristics of water pressure resistance and porous structure.

Example 2 1) Synthesis of polyalkylene oxide-modified polysiloxane 180 parts of dimethylpolysiloxane diol with an average molecular weight of 900 having two hydroxyl groups at the terminals and 4 parts of diphenylmethane
・After reacting with 76 parts of 4' diisocyanate at 90°C for 60 minutes, the molecular weight of the polypropylene oxide part was 50.
0 and 400 parts of Pluronic type polypropylene ethylene oxide diol having a polyethylene oxide moiety having a molecular weight of 1500 was added and the reaction was further carried out for 60 minutes to synthesize a urethane group-containing polyalkylene oxide-modified polysiloxane.

2) Preparation of polyurethane dispersion Polyurethane slurry prepared in Example 1 (^) 100
After adding 7.5 parts of the urethane group-containing polyalkylene oxide-modified polysiloxane obtained in 1) above per 1 part, water was added and mixed up to 30 parts while stirring with a homomixer.

When the resulting dispersion was stored at 40°C, the water-dispersed particles were stable at 1 μm or less even after 3 hours, and stable even after 1 day when stored at 25°C.

When a porous sheet was prepared in the same manner as in Example 1 using this dispersion after storage, the porous structure was fine and the moisture permeability was 6.
．． 5 B/cm" br and water pressure resistance of 1500 m.

Comparative Example 1 Table 2 shows the results of manufacturing a porous sheet in the same manner as in Example 1, except that the amount of PEO added in the synthesis of polyalkylene oxide-modified polysiloxane was 15%. When the -10 type dispersion obtained in this example is left standing at 40°C, the water-dispersed particles tend to aggregate and become coarse.
The dispersion stability of water was insufficient, and the porous sheet prepared from this dispersion had pinholes and coarse pores, which was not desirable.

Comparative Example 2 P[! in the synthesis of polyalkylene oxide-modified polysiloxane. Table 2 shows the results of manufacturing a porous sheet in the same manner as in Example 1 except that the amount of 0 added was 90%. When the type 10 dispersion obtained in this example was left standing at 40°C, the water dispersion stability was good, but the porous sheet obtained using this dispersion was a little solid and moisture permeable. was low.

Comparative Example 3.4 Example 1 (2) in preparation of water-containing polyurethane dispersion
A porous sheet was produced in the same manner as in Example 1, except that the amount of surfactant added was 0.05 part and 20 parts. When the amount of surfactant added was 0.05 part, when the Rim 10 type dispersion was allowed to stand at 40° C., the water-dispersed particles tended to aggregate and the porous structure became coarse, which was not preferable. Furthermore, when the amount of surfactant added is 20 parts, the dispersion stability of water is improved, but the evaporation of the solvent during formation of the porous sheet is suppressed, and the amount of residual solvent is reduced at the same drying time as in Example 1. The porous sheet thus obtained was a little fuller. So we took some time to slowly remove the solvent, and found that
Although it was possible to form fine pores, the strength of the porous sheet was poor and the result was not sufficient.

Comparative Example 5 The maximum amount of critical water added to the polyurethane dispersion prepared in Example 1-(2) was 4 parts per 100 parts of the polyurethane dispersion.
There were 5 parts. In contrast, the same polyurethane dispersion 10
When 50 parts of water was added to and mixed with 0 parts, gelation of the polyurethane resin occurred and stable %110110 parts could not be formed.

[Effects of the Invention] The polyurethane composition of the present invention can disperse a relatively large amount of water as fine particles, is stable, and has a polyurethane resin layer etc. that has a dense, air-permeable porous structure and excellent mechanical properties. A water-containing polyurethane dispersion can be obtained, and the surfactant does not ooze out from the formed polyurethane resin layer.

Claims (1)

[Claims] In a polyurethane composition that can form a water-containing polyurethane dispersion in which water is mixed and dispersed by adding water to an organic solvent composition of an organic solvent and a polyurethane resin having a water solubility of 1 to 50 g/100 g of organic solvent, a polysiloxane component A surfactant made of polyalkylene oxide-modified polysiloxane with a polyalkyl oxide component added thereto, in which the weight ratio of polyethylene oxide chains in the polyalkylene oxide component to the surfactant is 20 to 80%. 0.1 to 15 of the weight of polyurethane resin
%, and is characterized in that a stable water-containing polyurethane dispersion can be formed by adding water of 90% or less of the maximum critical water addition amount at which gelation occurs when water is added. thing.