JP6492491B2 - Aqueous polyurethane resin emulsion composition, artificial leather using the composition, and surface treatment agent for synthetic leather - Google Patents

Description

TECHNICAL FIELD The present invention relates to an aqueous polyurethane resin emulsion composition and a method for producing the same, and more particularly to an aqueous polyurethane resin synthetic leather having improved wear resistance using the emulsion composition and a surface treatment agent for artificial leather. It is.

The polyurethane resin composition is conventionally used exclusively as a composition using an organic solvent, and has high adhesion to various materials and excellent various properties, so that it can be used as a coating agent, paint, adhesive, printing ink, etc. It has been widely used.
In recent years, there has been a demand for an aqueous (aqueous) composition that does not use organic solvents because of environmental conservation and work safety, which are demands of society and industry, and it is economical because organic solvents are not used. In recent years, conversion to an aqueous polyurethane resin composition using an aqueous dispersion has been carried out universally.

Among water-based polyurethane resin compositions, polycarbonate-based polyurethane resin compositions are used for artificial leather, synthetic leather, natural leather, etc. because of their advantages such as hydrolysis resistance, heat resistance, wear resistance, and chemical resistance. In addition, by using a specific polycarbonate diol, a polyurethane emulsion that provides synthetic leather and artificial leather excellent in sweat resistance, hydrolysis resistance, flexibility, and the like has been proposed (Patent Documents 1 to 3).

JP 7-41539 A JP-A-2005-146089 JP2008-038281

However, the polyurethane emulsions described above have poor water dispersibility during production and insufficient wear resistance necessary for artificial leather and synthetic leather.

An object of the present invention is to provide an artificial polyurethane and an aqueous polyurethane resin emulsion composition for synthetic leather, which have good dispersibility during production and are excellent in flexibility and abrasion resistance.

That is, this invention is shown by the following 1-2.
1. Urethane prepolymer (D) obtained by reacting polyisocyanate (A) containing at least allophanate-modified diisocyanate (a1) and organic diisocyanate (a2), polyol compound (B), dimethylol fatty acid (C), and oxyethylene group The mixed polyisocyanate (E) is mixed, neutralized with the neutralizing agent (F), mixed with water and emulsified and dispersed, and then reacted with the chain extender (G). An aqueous polyurethane resin emulsion composition that satisfies the requirements of 1) to (5).
(1) Polyol compound (B) using 3-methyl-1,5-pentanediol (b1) and glycol (b2) other than (b1) as raw materials, molar ratio (b1) / (b2) = 50/50 A polycarbonate diol obtained by blending of ~ 99/1, wherein the polycarbonate diol has a number average molecular weight of 250 or more and 800 or less,
(2) The urethane prepolymer (D) is obtained by reacting at R (molar ratio of isocyanate group / hydroxyl group) = 1.2 to 1.5,
(3) The oxyethylene group-containing polyisocyanate (E) is obtained by reacting an allophanate-modified isocyanate with an active hydrogen compound having an oxyethylene group,
(4) The neutralizing agent (F) for performing the neutralization treatment is a basic neutralizing agent,
(5) The chain extender (G) is an amine compound having water and / or two or more primary or secondary amino groups.
2. A surface treatment agent for artificial leather and synthetic leather obtained using the aqueous polyurethane resin emulsion composition described in 1 above.
It is about.

In the present invention, the use of an isocyanate compound having a specific flexible structure and a polyol compound effective in improving abrasion resistance results in good dispersibility during production, and the resulting aqueous polyurethane resin emulsion has abrasion resistance. The surface treatment layer for synthetic leather and artificial leather excellent in oleic acid resistance and water resistance can be provided.

<Raw material of aqueous polyurethane resin emulsion composition>
Allophanate-modified diisocyanate The allophanate-modified diisocyanate compound used in the present invention is a main component material for increasing flexibility when used in synthetic leather and artificial leather in the aqueous polyurethane resin emulsion composition of the present invention. .

Specifically, allophanate-modified diisocyanate obtained from organic diisocyanate and monool is exemplified.
As the organic diisocyanate, aromatic diisocyanate, araliphatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate can be used, but in consideration of weather resistance, aliphatic diisocyanate and / or alicyclic diisocyanate are preferable. . In addition, these allophanate-modified polyisocyanate, isocyanurate-modified polyisocyanate, uretdione-modified polyisocyanate, urethane-modified polyisocyanate, burette-modified polyisocyanate, uretoimine-modified polyisocyanate, acylurea-modified polyisocyanate, etc. are used in combination as long as performance does not deteriorate. You can also.

<Aromatic diisocyanate>
Specific examples of the aromatic diisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate / 2,6-tolylene diisocyanate mixture, m-xylylene diisocyanate, p- Xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate / 4,4'-diphenylmethane diisocyanate mixture, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl- 4,4'-diisocyanate, 2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropylene Examples include lopan diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, naphthylene-1,4-diisocyanate, naphthylene-1,5-diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate.

<Aromatic aliphatic diisocyanate>
Specific examples of the araliphatic diisocyanate include 1,3- or 1,4-xylylene diisocyanate or a mixture thereof, 1,3- or 1,4-bis (1-isocyanato-1-methylethyl) benzene or a mixture thereof. , Ω, ω′-diisocyanato-1,4-diethylbenzene and the like.

<Aliphatic diisocyanate>
Specific examples of the aliphatic diisocyanate include hexamethylene diisocyanate, tetramethylene diisocyanate, 2-methyl-pentane-1,5-diisocyanate, 3-methyl-pentane-1,5-diisocyanate, lysine diisocyanate, and trioxyethylene diisocyanate. Can be mentioned.

<Alicyclic diisocyanate>
Specific examples of the alicyclic diisocyanate include isophorone diisocyanate, cyclohexyl diisocyanate, hydrogenated diphenylmethane diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated tetramethylxylene diisocyanate and the like.

Examples of monools include methanol, ethanol, 1-propanol, 2-propanol, n-butanol, isobutanol, n-pentanol, n-hexanol, and tridecanol.

In the polyisocyanate (A), the allophanate-modified diisocyanate is preferably contained in an amount of 10 to 70 mol%, more preferably 15 to 60 mol%. If it exceeds 70 mol%, the wear resistance is lowered, and if it is less than 10 mol%, the flexibility is undesirably lowered.
By containing an allophanate group in the polyisocyanate, a flexible and tough coating film can be formed, and a coating film having good flexibility and wear resistance can be obtained.

<Method for producing allophanate-modified diisocyanate (a1)>
First step: Monool and organic diisocyanate (a2) are urethanized at 20 to 100 ° C. in the presence or absence of an organic solvent by adding an excess amount of the isocyanate group to the hydroxyl group. By reacting, an isocyanate group-terminated prepolymer I for allophanate-modified diisocyanate is produced.
Second step: Allophanate-modified diisocyanate isocyanate group-terminated prepolymer I is charged with an allophanatization catalyst, and allophanated at 70 to 150 ° C. until substantially no urethane groups exist by infrared spectroscopic analysis (IR analysis). Thus, an isocyanate group-terminated prepolymer II for allophanate-modified diisocyanate is produced.
Third step: The reaction is stopped by adding a reaction terminator to the isocyanate group-terminated prepolymer II for allophanate-modified diisocyanate. In these first to third steps, the reaction is allowed to proceed under nitrogen gas or a dry air stream.
Fourth step: The isocyanate group-terminated prepolymer II for allophanate-modified diisocyanate is removed by thin film distillation or solvent extraction until the content of free organic diisocyanate is less than 1% by mass to produce allophanate-modified diisocyanate (a1).

Here, “the amount of the isocyanate group is excessive” means that the molar ratio of the hydroxyl group of the monool to the isocyanate group of the organic diisocyanate is 6 to 40 in terms of R = isocyanate group / hydroxyl group when the raw materials are charged. It is preferable to charge, and more preferably, R = 7-30. When the amount is less than the lower limit, the target product may contain a large amount of isocyanurate-modified polyisocyanate. When exceeding an upper limit, the polyisocyanate containing the urethane group which is a precursor of allophanate modification diisocyanate increases, and there exists a possibility of causing the fall of the number of functional groups, and the fall of productivity and a yield.

When the allophanate-modified diisocyanate is produced in the presence of an organic solvent, various organic solvents that do not affect the reaction can be used.
<Organic solvent>
Specific examples of the organic solvent include aliphatic hydrocarbons such as octane, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, ketones such as methyl isobutyl ketone and cyclohexanone, esters such as butyl acetate and isobutyl acetate, Ethylene glycol ethyl ether acetate, propylene glycol monomethyl ether acetate, 3-methyl-3-methoxybutyl acetate, glycol ether esters such as ethyl-3-ethoxypropionate, ethers such as dioxane, methylene iodide, monochlorobenzene, etc. And a polar aprotic solvent such as N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide, hexamethylphosphonylamide, and the like. These solvents can be used alone or in combination of two or more.

<First step: Step of producing isocyanate group-terminated prepolymer I for allophanate-modified diisocyanate>
The reaction temperature of the urethanization reaction in producing the isocyanate group-terminated prepolymer I for allophanate-modified diisocyanate is 20 to 120 ° C, preferably 50 to 100 ° C. In the urethanization reaction, a known urethanization catalyst can be used. Specifically, organic metal compounds such as dibutyltin diacetate, dibutyltin dilaurate and dioctyltin dilaurate, organic amines such as triethylenediamine and triethylamine, and salts thereof are selected and used. These catalysts can be used alone or in combination of two or more. The reaction time of the urethanization reaction varies depending on the presence or absence of the catalyst, the type, and the temperature, but is generally within 10 hours, preferably 1 to 5 hours is sufficient.

<Second step: Step of producing isocyanate group-terminated prepolymer II for allophanate-modified diisocyanate>
When the urethanization reaction is completed, an allophanate reaction is performed to produce an isocyanate group-terminated prepolymer II for allophanate-modified diisocyanate. At this time, the allophanatization reaction may be performed simultaneously with the urethanization reaction or after the urethanization reaction. When the urethanization reaction and the allophanatization reaction are performed simultaneously, the reaction may be performed in the presence of the allophanatization catalyst. When the allophanatization reaction is performed after the urethanization reaction, in the absence of the allophanatization catalyst, After performing the urethanization reaction for a predetermined time, an allophanatization catalyst may be added to carry out the allophanatization reaction.

<Allophanatization catalyst>
As the allophanatization catalyst used in the allophanatization reaction, it can be appropriately selected from known catalysts, and for example, a metal salt of a carboxylic acid can be used.
Specific examples of the carboxylic acid include acetic acid, propionic acid, butyric acid, caproic acid, octylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, 2-ethylhexanoic acid and other saturated aliphatic carboxylic acids, cyclohexanecarboxylic acid, Saturated monocyclic carboxylic acids such as cyclopentanecarboxylic acid, saturated polycyclic carboxylic acids such as bicyclo (4.4.0) decane-2-carboxylic acid, mixtures of the above carboxylic acids such as naphthenic acid, oleic acid, linoleic acid , Monocarboxylic acids such as linolenic acid, soybean fatty acid, unsaturated fatty carboxylic acid such as tall oil fatty acid, aromatic aliphatic carboxylic acid such as diphenylacetic acid, aromatic carboxylic acid such as benzoic acid and toluic acid; phthalic acid, Isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid, succinic acid, tartaric acid, oxalic acid, malonic acid, glutaric acid Adipic acid, pimelic acid, suberic acid, kurtaconic acid, azelaic acid, sebacic acid, 1,4-cyclohexyldicarboxylic acid, α-hydromuconic acid, β-hydromuconic acid, α-butyl-α-ethylglutaric acid, α, and polycarboxylic acids such as β-diethylsuccinic acid, maleic acid, fumaric acid, trimellitic acid, and pyromellitic acid.

In addition, as the metal constituting the metal salt of carboxylic acid, alkali metals such as lithium, sodium and potassium, alkaline earth metals such as magnesium, calcium and barium, other typical metals such as tin and lead, manganese, iron, Examples include transition metals such as cobalt, nickel, copper, zinc, and zirconium.
These carboxylic acid metal salts can be used alone or in combination of two or more. In addition, 0.001-0.1 mass% is preferable with respect to the total mass of a polyol and organic diisocyanate (a2), and, as for the usage-amount of an allophanatization catalyst, 0.005-0.03 mass% is more preferable. If it is less than the lower limit, allophanate-modified diisocyanate is not produced so much, the amount of by-products of urethane-modified polyisocyanate increases, and the number of functional groups of the resulting isocyanate decreases. Moreover, when exceeding an upper limit, there exists a possibility of causing the fall of storage stability.

Here, the reaction temperature of the allophanatization reaction is 70 to 150 ° C, preferably 90 to 130 ° C. When the reaction temperature is too low, allophanate-modified diisocyanate is not generated so much, the amount of by-products of urethane-modified polyisocyanate increases, and the number of functional groups of the resulting isocyanate decreases. Moreover, when reaction temperature is too high, the by-product of isocyanurate modification diisocyanate increases, and there exists a possibility of causing a fall of a softness | flexibility.

<Third step: Reaction stop step>
After the allophanatization reaction, a reaction terminator that deactivates the activity of the catalyst is added to stop the allophanate reaction. The addition timing of the reaction terminator is not particularly limited as long as it is after the allophanatization reaction. However, in order to suppress the progress of the side reaction, it is preferable to add the reaction terminator immediately after completion of the reaction.

<Reaction terminator>
Specific examples of the reaction terminator used here include inorganic acids such as phosphoric acid and hydrochloric acid, organic acids having a sulfonic acid group and a sulfamic acid group, and known compounds such as esters and acyl halides thereof. used. These can be used alone or in combination of two or more. Moreover, although the addition amount of a reaction terminator changes with kinds of catalyst, it is preferable to become 0.5-10 equivalent of a catalyst, and 0.8-5.0 equivalent is especially preferable. When the addition amount of the reaction terminator is small, the storage stability of the obtained allophanate-modified diisocyanate may be lowered. Moreover, when there is too much addition amount, there exists a possibility that coloring may arise.

After completion of the reaction step, a purification step for removing free unreacted organic diisocyanate can be performed. This purification step is mainly used when producing a low viscosity type allophanate-modified diisocyanate.
<Fourth step: Purification step>
In the purification step, the free unreacted organic diisocyanate present in the reaction mixture contains, for example, a residue of 1.0% by mass or less by thin film distillation at 120 to 140 ° C. under a high vacuum of 10 to 100 Pa. It is preferable to remove up to the rate. If the upper limit is exceeded, odor and storage stability may be reduced.
Further, when an organic solvent is used in the reaction step, it is removed in this purification step.

Thus, it is preferable to adjust the allophanate-modified diisocyanate (a1) obtained through a series of steps so that the isocyanurate-modified polyisocyanate does not exceed 5 mol% in terms of mole fraction. If the upper limit is exceeded, the flexibility may be reduced.

Next, organic diisocyanate (a2) will be described.
As the organic diisocyanate (a2), an aromatic diisocyanate, an araliphatic diisocyanate, an aliphatic diisocyanate, and an alicyclic diisocyanate can be used, but in consideration of weather resistance, an aliphatic diisocyanate and / or an alicyclic group. Diisocyanate is preferred. In addition, these allophanate-modified polyisocyanates (excluding (a1)), isocyanurate-modified polyisocyanates, uretdione-modified polyisocyanates, urethane-modified polyisocyanates, burette-modified polyisocyanates, uretoimine-modified polyisocyanates, and acylurea modifications as long as the performance does not deteriorate. Polyisocyanate etc. can also be used together.

<Aromatic diisocyanate>
Specific examples of the aromatic diisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate / 2,6-tolylene diisocyanate mixture, m-xylylene diisocyanate, p- Xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate / 4,4'-diphenylmethane diisocyanate mixture, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl- 4,4'-diisocyanate, 2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropylene Examples include lopan diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, naphthylene-1,4-diisocyanate, naphthylene-1,5-diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate.

<Aromatic aliphatic diisocyanate>
Specific examples of the araliphatic diisocyanate include 1,3- or 1,4-xylylene diisocyanate or a mixture thereof, 1,3- or 1,4-bis (1-isocyanato-1-methylethyl) benzene or a mixture thereof. , Ω, ω′-diisocyanato-1,4-diethylbenzene and the like.

<Aliphatic diisocyanate>
Specific examples of the aliphatic diisocyanate include hexamethylene diisocyanate, tetramethylene diisocyanate, 2-methyl-pentane-1,5-diisocyanate, 3-methyl-pentane-1,5-diisocyanate, lysine diisocyanate, and trioxyethylene diisocyanate. Can be mentioned.

<Alicyclic diisocyanate>
Specific examples of the alicyclic diisocyanate include isophorone diisocyanate, cyclohexyl diisocyanate, hydrogenated diphenylmethane diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated tetramethylxylene diisocyanate and the like.

The polyol compound (B) used in the present invention comprises 3-methyl-1,5-pentanediol (b1) and glycol (b2) other than 3-methyl-1,5-pentanediol (b1), dimethyl carbonate, diethyl Dialkyl carbonates such as carbonate, alkylene carbonates such as ethylene carbonate and propylene carbonate, diaryl carbonates such as diphenyl carbonate, dinaphthyl carbonate, dianthryl carbonate, diphenanthryl carbonate, diindanyl carbonate and tetrahydronaphthyl carbonate It can be obtained by dealcoholization reaction or dephenol reaction.

As glycol (b2), ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentane Diol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 3,3-dimethylolheptane, diethylene glycol, dipropylene glycol, neopentyl glycol, diethylene glycol, dipropylene glycol, cyclohexane-1 , 4-diol, cyclohexane-1,4-dimethanol, dimer acid diol, ethylene oxide or propylene oxide adduct of bisphenol A, bis (β-hydroxyethyl) benzene, xylylene glycol, glycerin, trimethylol group Mention may be made of bread, a low molecular weight polyols such as pentaerythritol.

The molar ratio of (b1) :( b2), which is a raw material for producing the polyol compound (B), is preferably 50:50 to 99: 1, and when 3-methyl-1,5-pentanediol is less than 50%, In addition to the poor water dispersibility, well-balanced flexibility and wear resistance cannot be obtained. The number average molecular weight of the polyol compound is preferably 250 or more and 800 or less. When the number average molecular weight is less than 250, the flexibility is insufficient, which is not preferable. When the number average molecular weight exceeds 800, the abrasion resistance is deteriorated, which is not preferable.

The dimethylol fatty acid (C) used to obtain the resin particles has two terminal hydroxyl groups, imparts hydrophilicity to the isocyanate group-terminated prepolymer obtained by reaction with isocyanate, and finally obtains a resin composition Is a hydrophilic group-containing monomer for making water-based.
Examples of the dimethylol fatty acid include dimethylol alkanoic acids such as dimethylol propionic acid (DMPA), dimethylol butanoic acid (DMBA), dimethylol pentanoic acid, and dimethylol nonanoic acid.

The urethane prepolymer (D) is preferably reacted at R (molar ratio of isocyanate group / hydroxyl group) = 1.2 to 1.5, and when it exceeds 1.5, the urea group concentration increases and flexibility decreases. It is not preferable. On the other hand, if it is less than 1.2, the molecular weight of the urethane prepolymer increases and the viscosity increases, so that the water dispersibility is greatly lowered, which is not preferable.

Examples of the oxyethylene group-containing polyisocyanate (E) used in the present invention include those obtained by reacting an allophanate-modified isocyanate with an active hydrogen group-containing compound having an oxyethylene group. Allophanate-modified isocyanates are obtained from organic diisocyanates and alcohols. As the organic diisocyanate, the same organic diisocyanate as mentioned in the production of allophanate-modified diisocyanate (a1) can be used.

As alcohol used for allophanate modification, monools such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol; ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, 2,2-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1, 3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, 2- Til-1,3-hexanediol, 2-n-hexadecane-1,2-ethylene glycol, 2-n-eicosane-1,2-ethylene glycol, 2-n-octacosane-1,2-ethylene glycol, diethylene glycol, Dipropylene glycol, 1,4-cyclohexanedimethanol, ethylene oxide or propylene oxide adduct of bisphenol A, hydrogenated bisphenol A, 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpro Diols such as pionate; and triols such as trimethylolpropane and glycerin. These may be used alone or in combination of two or more. In the present invention, 3-methyl-1,5-pentanediol is optimal in consideration of the balance of wear and flexibility.

Examples of the active hydrogen group-containing compound having an oxyethylene group include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, cyclohexanol, cyclohexene methanol, and other low-molecular monools, ethylene glycol Low molecular weight polyols such as low molecular weight polyols such as propylene glycol and glycerol, low molecular weight monoamines such as butylamine and aniline, low molecular weight polyamines such as ethylenediamine, hexamethylenediamine and isophoronediamine, and phenols such as phenol and hydroquinone It can be obtained by ring-opening addition of alkylene oxide containing ethylene oxide using a group-containing compound as an initiator. 50 mass% or more is preferable and, as for the oxyethylene group content in the active hydrogen group containing compound which has an oxyethylene group obtained, 70 mass% or more is especially preferable. In consideration of the viscosity of the resulting oxyethylene group-containing polyisocyanate, the alkali resistance of the coating, and the like, the initiator is preferably a low-molecular monool, and particularly preferably methanol or ethanol.

<Neutralizing agent>
Specific examples of the neutralizing agent include ammonia, ethylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-methyldiethanolamine, N-phenyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, Organic amines such as morpholine, N-methylmorpholine, 2-amino-2-ethyl-1-propanol, higher alkyl-modified morpholine, alkali metals such as lithium, potassium and sodium, inorganic alkalis such as sodium hydroxide and potassium hydroxide Etc. Further, from the viewpoint of improving the durability and smoothness of the coating film, a highly volatile neutralizing agent that is easily dissociated by heating, such as ammonia, trimethylamine, or triethylamine, is preferable. These neutralizing agents can be used alone or in combination of two or more.

Further, as another method for improving the water dispersion stability of the emulsion composition, an anionic polar group and a cationic polar group-containing compound can be used in combination.

<Anionic polar group-containing compound>
Specific examples of the anionic polar group-containing compound include an organic acid having one or more active hydrogen groups and a neutralizing agent. Examples of the organic acid include carboxylate, sulfonate, phosphate, phosphonate, phosphinate, and thiosulfonate, and these groups may be introduced independently or chelate. It may be related as follows.

<Cationic polar group-containing compound>
Specific examples of the cationic polar group-containing compound include a tertiary amine having one or more active hydrogen groups, a neutralizing agent for inorganic acids and organic acids, and a quaternizing agent. Specific examples of the tertiary amine having one or more active hydrogen groups include N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dipropylethanolamine, N, N-diphenylethanolamine, N-methyl-N-ethylethanolamine, N-methyl-N-phenylethanolamine, N, N-dimethylpropanolamine, N-methyl-N-ethylpropanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N- Methyldipropanolamine, N-phenyldiethanolamine, N-phenyldipropanolamine, N-hydroxyethyl-N-hydroxypropyl-methylamine, N, N'-dihydroxyethylpiperazine, triethanolamine, trisisopropanolamine, N Methyl - bis - (3-aminopropyl) - amine, N- methyl - bis - (2-aminopropyl) - amine. Moreover, what added the alkylene oxide to the 1st amine like ammonia and methylamine and the 2nd amine like dimethylamine can also be used.

Specific examples of inorganic and organic acids include hydrochloric acid, acetic acid, lactic acid, cyanoacetic acid, phosphoric acid and sulfuric acid. Specific examples of the quaternizing agent include dimethyl sulfate, benzyl chloride, bromoacetamide, chloroacetamide, or alkyl halides such as ethyl bromide, propyl bromide, and butyl bromide. Other cationic polar group-containing compounds include cationic compounds such as primary amine salts, secondary amine salts, tertiary amine salts, and pyridinium salts.

Next, the chain extender (G) used in the emulsion composition of the present invention will be described. The chain extender (G) is used as a chain extender of the composition, and by introducing it, durability against friction can be improved.

As the chain extender (G), mainly water or an amine compound having two or more primary or secondary amino groups is used, and an aliphatic diamine and / or an alicyclic diamine is preferably used. Specific examples of the amine compound include ethylenediamine, hexamethylenediamine, xylylenediamine, isophoronediamine, diethylenetriamine, N-aminoethyl-N-ethanolamine and the like. These chain extenders (G) can be used alone or in combination of two or more.

Resinization catalyst (urethanization catalyst) as a curing catalyst (polymerization catalyst) for urethanization reaction is used as necessary, and is a metal catalyst such as dibutyltin dilaurate, zinc naphthenate or bismuth compound, or triethylenediamine or N-methyl. A normal curing catalyst such as an amine-based catalyst such as morpholine is used, and the reaction rate can be increased and the reaction temperature can be lowered.

In the aqueous polyurethane resin emulsion composition of the present invention, a curing agent for curing the polyurethane resin may be appropriately used as necessary. In that case, it is used as one component of a two-component system (two-component composition) and is derived from hexamethylene diisocyanate (HDI) or isophorone diisocyanate (IPDI), and has 3 or more NCO groups in one molecule. Trimmer and adduct bodies are used. Specific examples include urethane-modified products, urea-modified products, allophanate-modified products, burette-modified products, uretdione-modified products, and isocyanurate-modified products of organic diisocyanates.

Widely used as various additives to enhance physical properties and add various physical properties, film forming agents, viscosity modifiers, anti-gelling agents, flame retardants, plasticizers, antioxidants, UV absorption Agents, antibacterial agents, fillers, internal mold release agents, reinforcing materials, matting agents, conductivity-imparting agents, charge control agents, antistatic agents, lubricants, dyes, pigments and other processing aids can be used.

The production of the aqueous polyurethane resin emulsion composition in the present invention involves the use of at least an allophanate-modified diisocyanate (a1) and an organic diisocyanate (a2), a polyisocyanate (A), a polyol compound (B), and dimethylol fatty acid for enhancing water dispersibility. The urethane prepolymer (D) is formed by performing a urethanization reaction according to (C), and then the oxyethylene group-containing polyisocyanate (E) for cross-linking is mixed, and the carboxyl group is neutralized with a neutralizing agent. After forming an acid salt, water is mixed and emulsified and dispersed, and further reacted with a chain extender (G) to extend the chain. The oxyethylene group-containing polyisocyanate may be prepared by reacting an isocyanate and an oxyethylene group-containing active hydrogen compound in advance, separately synthesized and mixed, or containing an organic diisocyanate and an oxyethylene group in the urethane prepolymer (D) system. A method in which active hydrogen compounds are mixed and reacted in the system may be used.

At the time of the synthesis of the urethane prepolymer (D), it may be diluted to an arbitrary solid content with an organic solvent which is inert to the isocyanate group. Examples of the organic solvent include aromatic solvents such as toluene, xylene, swazole (aromatic hydrocarbon solvent manufactured by Cosmo Oil Co., Ltd.), and Solvesso (aromatic hydrocarbon solvent manufactured by Exxon Chemical Co., Ltd.). , Aliphatic hydrocarbons such as hexane, alicyclic hydrocarbon solvents such as cyclohexane and isophorone, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, esters such as ethyl acetate, butyl acetate and isobutyl acetate Solvents, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, glycol ether ester solvents such as propylene glycol 3-methyl-3-methoxybutyl acetate, ethylene glycol ethyl-3-ethoxypropionate, Glycol dimethyl ether, diethylene glycol dibutyl ether, propylene glycol dibutyl ether, triethylene glycol monoethyl ether and dipropylene glycol dimethyl ether, tetrahydrofuran, ether solvents such as dioxane. The said solvent may contain 1 type (s) or 2 or more types.

In the present invention, a glycol ether ester solvent or a glycol ether solvent that has a high vapor pressure and does not exhibit a flash point even when present in an emulsion is preferred, and a glycol ether solvent that has particularly good hydrolysis resistance. Is preferred.

The blending ratio of the component (A) and the component (B) is preferably 100/10 to 100/95 mol% from the viewpoint of emulsification and film strength, and the use ratio of (a1) in the component (A) is described in paragraph 0016. As shown, 10 to 70 mol% is preferable. The amount of component (C) used is a ratio of 0.1 to 0.6 mmol / g in the resin from the viewpoint of the particle diameter of the resulting emulsion or the water resistance of the coating.
In the urethanization reaction, the usual urethanization catalyst described in paragraph 0020 may be used as a catalyst, and the reaction temperature may be about 50 to 100 ° C. as usual.

In the following, the ingredients of the present invention and the process for producing the emulsion will be presented, and by way of each example, while comparing each comparative example, the present invention will be shown in more detail, and the structure and effects of the present invention will be further enhanced. Clarify and demonstrate the rationality and significance of each requirement of the configuration of the present invention and its excellence over the prior art.

[Synthesis of allophanate-modified diisocyanate]
A reactor having a capacity of 1 L equipped with a stirrer, a thermometer, a cooler, and a nitrogen gas inlet tube was charged with 950 g of hexamethylenediamine (HDI), 50 g of isopropyl alcohol, and 0.1 g of zirconium octylate at 110 ° C. The reaction was performed for 4 hours. Next, 0.11 g of a phosphoric ester was charged, and a stop reaction was performed at 50 ° C. for 1 hour. The isocyanate content of the reaction product after the termination reaction was 40.5%. This reaction product was subjected to thin film distillation at 130 ° C. and 0.04 kPa to obtain allophanate-modified diisocyanate (ALP-1).
The isocyanate content was 19.3%, the viscosity at 25 ° C. was 100 mPa · s, and the free diisocyanate content was 0.1%. Moreover, when ALP-1 was analyzed by FT-IR and 13C-NMR, almost no urethane groups and isocyanurate groups were confirmed, and the presence of allophanate groups was confirmed.

A reactor having a capacity of 1 L equipped with a stirrer, a thermometer, a cooler, and a nitrogen gas introduction tube was charged with 925 g of hexamethylene diamine (HDI), 75 g of hexanol, and 0.1 g of zirconium octylate at 110 ° C. Time reaction was performed. Next, 0.11 g of a phosphoric ester was charged, and a stop reaction was performed at 50 ° C. for 1 hour. The isocyanate content of the reaction product after the termination reaction was 40.0%. This reaction product was subjected to thin film distillation at 130 ° C. and 0.04 kPa to obtain allophanate-modified diisocyanate (ALP-2).
The isocyanate content was 17.5%, the viscosity at 25 ° C. was 120 mPa · s, and the free diisocyanate content was 0.1%. Moreover, when ALP-2 was analyzed by FT-IR and 13C-NMR, almost no urethane groups and isocyanurate groups were confirmed, and the presence of allophanate groups was confirmed.

A reactor having a capacity of 1 L equipped with a stirrer, a thermometer, a cooler, and a nitrogen gas introduction tube was charged with 900 g of hexamethylenediamine (HDI), 100 g of tridecanol, and 0.1 g of zirconium octylate at 4 ° C. at 110 ° C. Time reaction was performed. Next, 0.11 g of a phosphoric ester was charged, and a stop reaction was performed at 50 ° C. for 1 hour. The isocyanate content of the reaction product after the termination reaction was 40.8%. This reaction product was subjected to thin film distillation at 130 ° C. and 0.04 kPa to obtain allophanate-modified diisocyanate (ALP-3).
The isocyanate content was 14.6%, the viscosity at 25 ° C. was 180 mPa · s, and the free diisocyanate content was 0.1%. Moreover, when ALP-3 was analyzed by FT-IR and 13C-NMR, almost no urethane groups and isocyanurate groups were confirmed, and the presence of allophanate groups was confirmed.

[Production of allophanate-modified isocyanate]
A reactor having a capacity of 1 liter equipped with a stirrer, a thermometer, a cooler, and a nitrogen gas inlet tube is 950 g of hexamethylenediamine (HDI), 50 g of 3-methyl-1,5-pentanediol, and 0 of zirconium octylate. .1 g was charged and reacted at 110 ° C. for 4 hours. Next, 0.04 g of phosphoric acid was added and a stop reaction was performed at 80 ° C. for 1 hour. The isocyanate content of the reaction product after the termination reaction was 40.3%. This reaction product was subjected to thin film distillation at 130 ° C. and 0.04 kPa to obtain allophanate-modified polyfunctional isocyanate (ALP-4).
The isocyanate content was 19.3%, the viscosity at 25 ° C. was 1800 mPa · s, and the free diisocyanate content was 0.1%. Moreover, when ALP-4 was analyzed by FT-IR and 13C-NMR, almost no urethane groups and isocyanurate groups were confirmed, and the presence of allophanate groups was confirmed.

[Production of isocyanurate-modified polyisocyanate]
A reactor having a capacity of 500 ml equipped with a stirrer, thermometer, nitrogen seal tube, and condenser was charged with 300 g of hexamethylene diisocyanate (HDI) and 2.8 g of 1,3-butanediol (1,3-BD). Thereafter, the inside of the reaction vessel was purged with nitrogen, heated to a reaction temperature of 80 ° C. with stirring, and reacted at the same temperature for 2 hours. When the isocyanate content of this reaction liquid was measured, it was 48.6%. Next, 0.06 g of potassium caprate as a catalyst and 0.3 g of phenol as a cocatalyst were added, and an isocyanate reaction was performed at 60 ° C. for 6 hours. 0.042 g of phosphoric acid was added to this reaction solution as a terminator, and after stirring for 1 hour at the reaction temperature, free HDI was removed by thin-film distillation under the conditions of 120 ° C. and 1.3 kPa, and isocyanurate-modified polyisocyanate (PolyNCO- 1) was obtained.
It was a pale yellow transparent liquid, an isocyanate content of 21.3%, a viscosity at 25 ° C. of 2,200 mPa · s, and a free HDI content of 0.3%.

[Production of polyol compound 1]
To a reaction apparatus including a stirrer, a thermometer, a heating device, and a distillation tower, 3-methyl-1,5-pentanediol (hereinafter abbreviated as MPD) and 1,6-hexanediol (hereinafter referred to as 1,6-hexane) are used as glycols. HG.) Is set to MPD / 1,6-HG = 1/1 by molar ratio, and the blending ratio of this glycol to diethyl carbonate (hereinafter abbreviated to DEC) is 1.38 by molar ratio. MPD 462 g, 1,6-HG 462 g and DEC 671 g were charged, and 0.05 g of tetrabutyl titanate (hereinafter abbreviated as TBT) was added as a reaction catalyst, and the temperature was gradually raised to 190 ° C. under a nitrogen stream. Raised. When the distillation of ethanol slows down and the top temperature of the distillation column becomes 50 ° C. or lower, the pressure is gradually reduced to 1.3 kPa while maintaining the reaction temperature at 190 ° C., and further at a pressure of 1.3 kPa for 7 hours. Reacted. Further, the reaction was continued at a reaction temperature of 190 ° C. under a reduced pressure of 1.3 kPa or less until the hydroxyl value of the reaction product reached 218 to 230 (mg-KOH / g) to obtain a polyol compound (Polyol-1). The resulting polyol compound had a number average molecular weight of 500 (hydroxyl value; 224.4 mg-KOH / g).

[Manufacture of polyol compound 2]
In the same production method as that for the production of polyol compound 1, MPD / 1,6-HG = 9/1 and MPD 832 g, 1,6-HG so that the blending ratio with respect to DEC is 1.38 in molar ratio. Was synthesized in the same manner except that 92.5 g and 671 g of DEC were charged to obtain a polyol compound (Polyol-2) having a number average molecular weight of 500 (hydroxyl value 224.4 mg-KOH / g).

[Manufacture of polyol compound 3]
In the same production method as the production of polyol compound 1, MPD / 1,6-HG = 5/5, MPD was 446 g, 1,6-HG so that the blending ratio with respect to DEC was 1.25 in molar ratio. Was synthesized in the same manner except that 446 g and 714 g of DEC were charged to obtain a polyol compound (Polyol-3) having a number average molecular weight of 701 (hydroxyl value 160.0 mg-KOH / g).

[Production of polyol compound 4]
In the same production method as in Production 1 of the polyol compound, MPD / 1,6-HG = 9/1, MPD was 802 g, 1,6-HG so that the blending ratio with respect to DEC was 1.25 in terms of molar ratio. Was synthesized in the same manner except that 89.1 g of DEC and 714 g of DEC were charged to obtain a polyol compound (Polyol-4) having a number average molecular weight of 700 (hydroxyl value: 160.2 mg-KOH / g).

[Manufacture of polyol compound 5]
In the same production method as in Production of polyol compound 1, 925 g of DEC, 1,6-HG, DEC, so that MPD / 1,6-HG = 0/10 and the mixing ratio with respect to DEC is 1.38 in molar ratio. The polyol compound (Polyol-5) having a number average molecular weight of 500 (hydroxyl value 224.4 mg-KOH / g) was obtained.

[Manufacture of polyol compound 6]
In the same production method as the production of polyol compound 1, MPD / 1,6-HG = 9/1, and MPD was 757 g, 1,6-HG so that the blending ratio with respect to DEC was 1.16 in molar ratio. Was synthesized in the same manner except that 84.1 g and 723 g of DEC were charged to obtain a polyol compound (Polyol-6) having a number average molecular weight of 1000 (hydroxyl value: 112.2 mg-KOH / g).

[Manufacture of polyol compound 7]
In the same production method as the production of polyol compound 1, MPD / 1,6-HG = 9/1, MPD was 747 g, 1,6-HG so that the blending ratio with respect to DEC was 1.08 in molar ratio. Was prepared in the same manner except that 83.0 g of DEC and 771 g of DEC were charged to obtain a polyol compound (Polyol-7) having a number average molecular weight of 2004 (hydroxyl value: 56.0 mg-KOH / g).

[Production of polyurethane resin emulsion]
In a 1 L reactor equipped with a stirrer, thermometer, nitrogen seal tube, and condenser, 117 g of Polyol-1 (MPD / 1, 6HG = 5/5, Mn = 500), dimethylolpropionic acid (DMPA) 8.3 g), dipropylene glycol dimethyl ether (DMDPG) 100 g, isophorone diisocyanate (IPDI) 41.6 g, and ALP-1 100 g were charged, heated to 85 ° C., and reacted at the same temperature for 3 hours. The isocyanate content of this prepolymer solution was 2.7%. Next, 13.3 g of ALP-4 and 13.3 g of methoxypolyethylene glycol having a number average molecular weight of 400 were charged and reacted at 70 ° C. for 45 minutes. Next, 6.3 g of triethylamine (TEA) was charged to neutralize the carboxyl group, and then 557 g of water was charged and emulsified with stirring. Within 30 minutes after emulsification, amine water (containing 36.3 g of water and 6.4 g of ethylenediamine (EDA)) was charged, and an amine chain extension reaction was performed at 30 ° C. for 12 hours. When the presence of isocyanate groups was no longer confirmed by FT-IR, an aqueous polyurethane emulsion (PUD-1) was obtained.

[Manufacture of other polyurethane resin emulsions]
The feed composition (blending amount; mass) of each raw material was as shown in Tables 1 and 2, and PUD2 to PUD15 were produced in the same manner as in the production of PUD-1.

The properties of the obtained aqueous polyurethane emulsion were confirmed for the following items, and the results are shown in Tables 1 and 2.
1. In the production of the dispersible polyurethane resin emulsion, “◯” indicates that a uniform dispersion can be obtained in the water emulsification dispersion step, and “x” indicates that a large amount of aggregates are generated or separation occurs.
2. The obtained aqueous polyurethane resin composition and the polyurethane resin contained in the solid content were measured for each mass, the ratio of the polyurethane resin mass to the mass of the aqueous polyurethane resin composition was calculated, and the obtained aqueous polyurethane resin composition was obtained The non-volatile content (mass%) of was determined.
3. Viscosity After adjusting the obtained aqueous polyurethane resin composition so that the liquid temperature was 25 ° C., a B-type viscometer (manufactured by Toki Sangyo Co., Ltd., product name: TVB-22L, rotor number used: No .2) was measured at a rotational speed of 60 rpm, and the viscosity (mPa · s at 25 ° C.) of the obtained aqueous polyurethane resin composition was determined.
4). The obtained aqueous polyurethane resin composition having an average particle diameter was subjected to a light scattering photometer (manufactured by Otsuka Electronics Co., Ltd., product name: ELS-800), analyzed by the cumulant method, and the polyurethane in the obtained aqueous polyurethane resin composition The average particle size of the resin was determined.

<Film production method>
To 100 parts of the aqueous polyurethane resin composition obtained in Examples 1 to 7 and Comparative Examples 1 to 5, 7 and 8, 1.5 parts of a 10% aqueous solution of leveling agent TEGOWetKL-245 (Evonik product) was added, and The main component was obtained by diluting and mixing with water so that the solid content was 20%. The main agent was applied so that the dry film pressure was 20 μm, and dried at 25 ° C. for 1 week to prepare a cured product. Using this cured product, physical properties were evaluated.

About the obtained film, the following items were evaluated and the results are shown in Tables 3 and 4.
1. Tensile properties (each modulus, strength at break, elongation at break)
A sample was punched out from the obtained film with a No. 4 dumbbell cutter, and this was measured according to JIS K7311. The tensile speed was 200 mm / min, and the measurement temperature was 25 ° C.
2. Water resistance The sample was punched out with a No. 4 dumbbell cutter, and the tensile strength was measured according to JIS K7311. The tensile speed was 200 mm / min, and the measurement temperature was 25 ° C. Similarly, the film was allowed to stand at 85 ° C./95% RH for 4 weeks, and the tensile strength retention rate (%) was measured. A sample having a retention rate of 80% or more was indicated by “◯”, and a sample having a retention rate of “%” or lower.

<Evaluation as a synthetic leather surface treatment layer>
First, using the aqueous polyurethane resin compositions obtained in Examples 1 to 7 and Comparative Examples 1 to 5, 7, and 8, (1) to (6) were mixed and filtered according to the following surface treatment formulation, respectively. The surface treatment layer formulation liquid was produced by mix | blending the main ingredient and mixing it with the compounding ratio of hardening | curing agent AQ-130 (EEP solvent 50% solution) and main ingredient / hardening agent = 80/20.
Next, the surface treatment was applied to the surface of a commercially available polyurethane-based synthetic leather (100 × 100 mm) using a spray machine so that the dry coating amount was 0.05 g / 100 cm ^2. Two coats of the heat treatment were carried out by standing for 3 minutes in a drier adjusted to ° C. Then, after curing at 25 ° C. for 1 week, the surface layer was evaluated using this synthetic leather.
Main agent: Solid content = 25%
(1) PUD resin: 60 parts (2) ACEMATT OK412 (matting agent EVONIK product): 4.5 parts (3) BYK-SILCLEAN3720 (slip agent Big Chemie Japan product): 4.0 parts (4) Aqualene SB- 630 (antifoaming agent Kyoeisha Chemicals): 0.5 part (5) TEGOWet 280 (leveling agent EVONIK product): 1.0 part (6) Water: 30 parts

About the obtained synthetic leather which gave the said synthetic | combination surface treatment, the following items were evaluated and the result was described in Table 3 and Table 4.
1. Regarding flexibility, “◯” indicates that the elongation in the film tensile property test is 530% or more, and “X” indicates that it is lower than that.
2. Abrasion resistance The synthetic leather obtained is subjected to a Gakushin friction fastness tester (manufactured by Tester Sangyo Co., Ltd., product name: AB-301), and the number of wear at a load of 2 kgf is more than 2000 times. ”, 1000 to 2000 times,“ Δ ”, and lower ones“ x ”.
3. Oleic acid resistance The synthetic leather obtained was subjected to an oleic acid spot test (1 drop), wiped off after 24 hours at room temperature, and the appearance was observed. The case where the skin layer was good without change was indicated as “◯”, and the case where the skin layer was rough or torn was indicated as “X”.

Claims (2)

At least allophanate-modified diisocyanate (a1), and polyisocyanates containing an organic diisocyanate (a2) (A), polyol compound (B), and dimethylol fatty (C) a urethane prepolymer obtained by reacting (D), Oxyethylene group-containing polyisocyanate (E) is mixed, neutralized with a neutralizing agent (F), mixed with water and emulsified and dispersed, and then reacted with a chain extender (G). A method for producing an aqueous polyurethane resin emulsion composition that satisfies the following requirements (1) to (5) :
(1) Polyol compound (B) using 3-methyl-1,5-pentanediol (b1) and glycol (b2) other than (b1) as raw materials, molar ratio (b1) / (b2) = 50/50 A polycarbonate diol obtained by blending of ~ 99/1, wherein the polycarbonate diol has a number average molecular weight of 250 or more and 800 or less,
(2) The urethane prepolymer (D) is obtained by reacting at R (molar ratio of isocyanate group / hydroxyl group) = 1.2 to 1.5,
(3) oxyethylene group-containing polyisocyanate (E) is intended to include the active hydrogen compound having an allophanate-modified isocyanate and an oxyethylene group,
(4) The neutralizing agent (F) for performing the neutralization treatment is a basic neutralizing agent,
(5) The chain extender (G) is an amine compound having water and / or two or more primary or secondary amino groups. The method according to claim for artificial leather surface treatment agent obtained by using an aqueous polyurethane resin emulsion composition according to 1, or synthetic leather surface treatment agent.