JPS60144318A - Production of porous sheet material - Google Patents

Abstract

PURPOSE:To produce the titled flexible sheet material free of macropores and having a uniform microporous structure, by coating a base with a linear polyurethane resin solution containing a specified OH group-containing urethane prepolymer and subjecting this base to wet treatment. CONSTITUTION:An OH group-terminated urethane prepolymer is obtained by reacting an organic diisocyanate with a polyoxyalkylene-modified dimethylpolysiloxanes of formulas I and II (wherein R is a 2-5C linear or branched alkylene, R1 and R2 are each ethylene and/or branched propylene, m and n are each a degree of polymerization of a polyoxyalkylene and has a value such that the number of oxyalkylenes in the molecule is 5-50, x is 2-50, y is 2-30, and 4<=x+y<=50) at a molar ratio of 1:1.1-2. 0.1-20wt%, based on solid matter, above urethane prepolymer is added to a solution of a linear polyurethane resin, and a base is coated or impregnated with the obtained mixture. This base is immersed in a coagulation bath to coagulate the resin by extraction of the solvent.

Description

[Detailed description of the invention] The present invention relates to a method for producing a porous sheet material.

Ru.

When a microporous coating layer is laminated onto a substrate, the sheet material becomes more similar to leather in terms of durability, appearance and feel, and is therefore used as a substitute for leather. However, various proposals have been made so far to obtain a sheet material with uniform micropores, but none of them have been fully satisfactory. For example, as described in Japanese Patent Publication No. 49-9722, there is a method of adding polyethylene glycol monostearate to a urethane resin solution and performing wet coagulation, but now even denser and more flexible products are required. It's starting to look like this, and I'm not satisfied with it.

Under such circumstances, the present inventors conducted intensive research and arrived at the present invention. Namely, the present invention involves applying a polyurethane resin solution having a substantially linear structure to a substrate and wet-processing it to form a porous sorting material. In the method for producing polyoxyalkylene-modified dimethylpoly/loxane CB) represented by the following formula [l] and/or [1] in an excess equivalent amount with organic diisonane-1-(A) in the polyurethane resin solvent solution. , it is a linear or branched alkylene group of c2 to C5, and IL is a numerical value of an ethylene group or a branched propylene, and satisfies 4≦x10y≦50. ) When the hydroxyl group-terminated urethane prepolymer is contained in an amount of 01 to 20mM% based on the solid content of the polyurethane resin solution, the amount of socia dispersion and excess amount is expressed by the aiJ notation ('l) and/or (1). The polyoxoalkylene parent compound can be produced by reaction with raw dimethylpolysiloxane, but the ratio of the two during the reaction is -1-1 mole of polyoxoalkylene-modified dimethylpolysiloxane to 1.1 to 1 mole of polyoxyalkylene modified dimethylpolysiloxane. It is 2 moles.

The urethane compound may also partially contain unreacted polyoxyalkylene-modified dimethylpolysiloxane or organic diisocyanate.

Organic diisocyanin-1, which is a raw material for producing the compound of the present invention
・The binding is 1,6-hexamethylene diisocyanate,
■, 4-cyclohexane diisocyanate! Inholonodiisocyanate, 1-,4,4'-dicyclohexylmethane diisocyanate, 2,4- and 2,6-toluylene diisocyanate, 1n- and P-xylene diisocyanate, etc., which are usually used in the production of polyurethane. Diisocyanate I. is fine. The polyoxyalkylene-modified dimethylpolysiloxane, which is the other raw material for producing the compound of the present invention, is a polyoxy/alkylene-modified dimethylpolysiloxane represented by the formula [■] and/or [R], where R in [l] is is preferably ethylene, propylene, n-butylene, 1so-butylene group, etc.
-butylene group, more preferably propylene or lobetylene group. Both groups do not necessarily have to be the same, and may be different, such as propylene and n-butylene groups. river.

Horse is a group in which ethylene, branched propylene or both ethylene and branched propylene are present, and is usually formed by an addition reaction of ethylene oxide and/or propylene oxide.

One of m or l may be 0, but preferably both are 1.
In the above, m tenn is 5 to 50, preferably lθ to 40
It is. X is 2-50. The molecular weight is preferably 5 to 30, and the overall molecular weight is usually 500 to 6,000, preferably [1,000
~5000. The ratio of molecule 1.1 of the dimethylsoloxane moiety to molecule 11 of the polyoxyalkylene moiety is 1:3 to 3.
:1, preferably 1:2 to 2:], that is, the degree of polymerization of dimethylsiloxane units and oxyalkylene units is 2 to 50:5 to 50. preferably 5 to 80
: 10-40, more preferably 10-20: 1
Compounds ranging from 5 to 80 can be used. Specific examples of these compounds include Silicone 5F manufactured by Toray Silicon Co., Ltd.
-8427, etc. In [mouth], 几 is ethylene, propylene, n-butylene, 'is.

Examples include butylene groups. Among these, ethylene, propylene, and n-butylene groups are preferred, and propylene and n-butylene groups are more preferred. % Ru 25-50, preferably 10-40sx is 2-50°, preferably 5-3
0 and y are 2 to 30, preferably 2 to 20, and the overall molecular weight is usually 500 to 6000, preferably 1000.
~5000, the ratio of the molecular weight of the dimethylsiloxane moiety to the molecular weight of the polyoxyalkylene moiety is 1:8~3:1,
Preferably, a ratio of 1:2 to 2.1 is used. Therefore, the range of the degree of polymerization of the polysiloxane moiety and the degree of polymerization of the oxyalkylene represented by 0- is the same as the range in (1). More specifically, silicone 5F8428 manufactured by Toshi Silicon Co., Ltd. can be used.

The urethane compound of polyoxyalkylene-modified dimethylpolysiloxane and diisocyanate represented by formula CI) or formula [1] is, for example, 1 mole of diisocyanate such as 4,4'-diphenylmethane diisocyanate per 2 moles of polyoxyalkylene-modified dimethylpolysiloxane. It is obtained by reacting at about 70° C. for 3 hours under a dry nitrogen atmosphere. The reaction conditions may be those normally used for producing urethane resins. The resulting urethane compound is a mixture of a reactant containing 1 mole of A and 2 moles of B, and a polymerized linear structural polymer obtained from a reactant containing 1 mole of A and less than 2 moles of B, and has an average molecular weight of 2000.
~20,000, more preferably 4,000 to 15,000, in the form of a paste or white wax, and must be soluble or uniformly dispersed in the bath medium of the urethane resin to be blended.

The amount of the urethane compound added to the polyurethane resin solution is 01 to 65% based on the solid content of the polyurethane resin solution.
20% by weight, especially 05-10% by weight? - is preferred. The polyurethane resin having a substantially linear structure in the present invention is one obtained by reacting an organic diisocyanate with a polymeric diol and a chain extender. Organic/Isosoameric-1.

The polymeric diol and chain extender are conventional ones, such as those described in JP-A-54-88996, JP-A-58-16796@, JP-A-58-42294g, and JP-A-58-42294. Showa 54-18069
The one disclosed in Publication No. 9 can also be used. Specifically, the organic diisocyanates include aliphatic, alicyclic or aromatic diisocyanates, and diphenylmethane diisocyanate (MDI) or an organic diisocyanate mainly composed of this is preferred.

Polyether diol is a polymeric diol.

Polyester diol and polyether ester diol are available. The average molecular weight (by hydroxyl value measurement) of the molecular diol is usually 500 to 5,000, preferably Huff 00 to 4,000, particularly preferably U 1,000 to 800.
It is 0. Examples of chain extenders include low molecular weight glycols with a molecular weight of less than 500, diamines, hydrazine, monoalkylhydrazines, alkanolamines, and mixtures of two or more thereof. The amount of the chain extender used and the ratio of the organic diisocyanate to the polymeric diol and the chain extender may be the same as in the usual case.
The description in JP-A-88996 can be applied. For example, the amount of chain extender used is usually 0 in molar ratio to the polymeric diol.
It is 5 or more, preferably 1-10. In addition, it is 1 in terms of organic/isocyan.

Regarding the solvent that can be used in the production and reaction of polyurethane resin, conventional methods may be used.
The description in the publication can be applied. For example, the method of manufacturing polyurethane resin is the hunting method, the one-shot method,
Prepolymer methods can be used. Specific examples of the solvent include amide thread solvents such as methylformamide (DMF) and dimethylacetamide, sulfoxide solvents such as dimethyl sulfoxide (DΔ180), ether threading agents such as tetrahydrofurano and oxane, and ace 1-noamethyl ethyl ketone. Ketone solvents and mixed solvents of two or more of these solvents can be used. Especially 1) M,
F is preferred. The solvent may be present from the beginning of the reaction or may be present from the middle (after the prepolymer production).

The organic solvent solution of the polyurethane resin having a substantially linear structure used in the present invention may be prepared by reacting this organic diison, a polymeric diol, and a chain extender in the presence of the solvent and diluting it as necessary. Alternatively, it may be reacted without a bath agent and then dissolved in a solvent. 4 of polyurethane resin organic solvent solution? The urethane resin concentration is usually 5 to 40% by weight.
It is.

The polyurethane resin solution may contain resins other than polyurethane resins, such as polyvinyl chloride, polyacrylate, polymethacrylate, soristyrene, polyacrylonitrile, acrylonitrile-vinylidene chloride copolymer, and vinyl chloride.

A vinyl acetate copolymer may also be blended. However, if necessary, antioxidant (4,4'-butyrythene-bis(3)
Hindered phenols such as -methyl-6-t-butylphenol);
UV absorbers (Pezphenone type, benzotriazole type, etc.), carboxylic acids.

Stabilizers such as phosphoric acid, oxycarboxylic acid, norogenated phenol, and pigments (titanium oxide, carbon black, etc.)
, fillers (cal/rum carbonate, etc.), plasticizers, antistatic agents, bactericides, known coagulation regulators, etc. can be separated. Substrates used in the present invention may be of the gods. Woven fabrics made of various natural or synthetic fibers (polyamide, polyester, rayon, wool, cotton, etc. and mixtures thereof), non-woven fabrics, felt, brushed fabrics and paper, plastic films, gold JfJ4&, glass boards, etc. can be opened.

The present invention relates to a method for producing a sorting ladle. The method of manufacturing a polyurethane resin having a substantially linear structure is carried out in the same manner as the conventional wet coagulation method except that the liquid contains a urethane compound. I can do it. In other words, an organic solvent solution containing a polyurethane resin having a substantially linear structure as a main component is applied to the substrate and impregnated into the substrate, and the organic solvent has an affinity with the 41 solvent and has no affinity with the polyurethane resin. A porous sorting material can be produced by treatment with a certain non-solvent. Methods for making the urethane compound present in the solution include adding the urethane compound as it is to the organic solvent solution of the resin; An example is a method in which the resin is once dissolved or dispersed in an organic solvent and then added to an organic solvent solution of the resin. A specific method for wet coagulation is, for example, applying or impregnating a polyurethane resin solution onto a substrate, and then immersing it in a coagulation bath that is compatible with the organic solvent described in 6iJ and non-solvent for the polyurethane resin to extract the solvent. How to coagulate by. One example is a method in which a substrate is impregnated with a polyurethane resin solution and then coagulated in a vapor atmosphere from a non-solvent. Examples of solvents that are compatible with the above organic solvents and are non-solvents for polyurethane resins include water, methanol, ethylene glycol, and glycerin. Usually water is used. Also DMF/
A mixed solvent of water can also be used.

In the present invention, known surfactants (cationic, a""t) type +
(nonionic) may be present in the polyurethane resin solution. A polyurethane resin solution according to the present invention and a polyurethane resin solution other than the present invention (-1J activator may or may not be present) are used together to be applied to a substrate, and D Wi h construction is performed. You can also use it as For example, the substrate may be impregnated with a polyurethane resin solution other than the one according to the invention, and then the polyurethane resin solution according to the invention may be applied before or after wet coagulation. The polyurethane resin solution of the present invention may be applied to the substrate more than once.

The porous material obtained in the present invention has a urethane resin layer with extremely homogeneous micropores, and has a soft texture and a smooth surface.

The notebook (A material) produced according to the present invention can be used as a leather substitute for shoe bags, furniture, clothing, farmed products, vehicles, etc. A substitute for smooth or suede leather. It is also possible to do this.

The present invention will be explained below with reference to examples, but the present invention is not limited thereto. Parts in the examples represent parts by weight.

Examples 1-2. Comparative Examples 1 to 3 Poly[ethylene/butylene (molar ratio 1/1)) adipate 188p ethylene cricoli 1 with an average molecular weight of 2220
0. @Oyohi 57 g of 4.4' diphenylmethane diisocyanate was added to 800.9 g of dimethylformamide and reacted in a dry nitrogen atmosphere to form a substantially linear polyurethane resin solution with a resin concentration of 20% and a viscosity of 80 voids (20°C). Obtained. Using this solution, solutions having the compositions shown in Table 1 were prepared.

Table 1 Urethane compound (1) 4. Reaction product of 1 mol of 4'-diphenylmethane diisocyanate and 2 mol of polyoxyalkylene-modified dimethylpolysiloxane I Urethane compound (2) 2.4 Diisocyane-1・
Reaction product of 1 mole with 2 moles of polyoxyalkylene-modified dimethylpolysiloxane Compound A, polyoxyalkylene-modified dimethylborine xane compound B: 7 moles of EO of stearyl alcohol: j Additive compound C: 9 moles of E0 of stearic acid Each of the additive upper adjustment solutions was cast onto a glass plate to a thickness of 1.2 mm,
The porous sheet was immersed in a water bath adjusted to 40°C for 60 minutes to solidify, then removed from the glass plate, washed with room temperature water for 10 minutes, and dried with hot air at 80°C. 1. Shape and properties of the obtained sheet. are shown in Table 2.

Examples 3-4. Comparative Examples 4 to 7 122 g of polyoxytetramethylene glycol with an average molecular weight of 2050, 16.5 g of 1,4' butylene dalicol
, 9° and 4,4'-diphenylmethane diisocyanate 61.5.9 Added to 800 g of dimethylformamide and reacted in a dry nitrogen atmosphere to form a substantially linear polyurethane with a resin concentration of 20% and a viscosity of 20 poise (20°C). A resin solution was obtained. Using this solution, solutions having the compositions shown in Table 3 were prepared.

Urethane compound (3) 4. Reaction product of 2 moles of 4'-diphenylmethane diisocyanate and 8 moles of polyoxyalkylene-modified dimethyl polysiloxane Urethane compound (4) 4. 2 moles of 4'-diphenylmethane diisocyanate and 8 moles of polyoxyalkylene-modified dimethylpolysiloxane Reaction product with 3 moles of polyoxyalkylene-modified dimethylpolysiloxane Compound D: Polyoxyalkylene-modified dimethylpolysiloxane compound E: Polyoxyalkylene-modified dimethylpolysiloxane compound F: Nilarubikune monooleate compound G of nistearic acid Button 8 mol adduct The above prepared solution was cast onto a glass plate with a thickness of 12 mm and heated at 40°C.
exposed to an atmosphere of 95% humidity for 6 minutes, and further heated to 40°C.
Immerse it in a water bath adjusted to 30 minutes to solidify it, then remove it from the glass plate and wash the porous plate with room temperature water for 30 minutes.
It was dried with hot air at 0°C. Table 4 shows the shape and properties of the sheet obtained.

Example-5 A solution colored by adding a black pigment to the prepared solution in Example-1 was applied to a brushed cotton fabric to a thickness of 1.0 mm.) Immediately immersed in water at room temperature for 10 minutes, and then immersed in warm water at 50°C. 4
After being immersed for 5 minutes and removing the solvent, it was washed with water and dried.

By grinding the surface of the obtained sheet-like material, suede-like synthetic leather with excellent appearance, feel, and texture was obtained.

Patent applicant: Sanyo Chemical Industries, Ltd.

Claims (1)

[Claims] 1. In a method for producing a porous sheet material by applying a substantially linear polyurethane resin solution to a substrate and wet-processing the polyurethane resin solution, an excess of organic diisocyanate (A) is added to the polyurethane resin bath solution. equivalent of the following formula CI) and/or [1]
Polyoxyalkylene-modified dimethylpolysiloxane (B) represented by
Alternatively, the value of branching is from 2 to 80, and 4≦x+y≦50. ) A method for producing a porous sheet material, characterized in that the hydroxyl-terminated urethane prepolymer is contained in an amount of 01 to 20% by weight based on the solid content of the polyurethane resin solution. 2. The production method according to claim 1, which uses reactants in which the molar ratio of (A) and CB) is 1:1.1 to 2.