JPH0481414A - Production of polyurethane resin - Google Patents

Abstract

PURPOSE:To obtain the title resin having excellent dispersibility of solid such as pigment or magnetic powder, useful for synthetic leather having high luster by reacting a glycol containing plural alkyl group side chains wherein the alkyl groups have plural carbon atoms with a diisocyanate. CONSTITUTION:In producing a polyurethane resin by reacting a diol with a diisocyanate, a polyester diol (A) a glycol containing two or more alkyl group side chains wherein at least one of the alkyl groups is an alkyl group having >=2 carbon atoms or a glycol (e.g. 2-ethyl-1,3-hexanediol) containing three or more methyl glycols as the diol and (B) a dicarboxylic acid (e.g. adipic acid) is reacted with (C) the diisocyanate (e.g. 2,4-tolylene diisocyanate) to give the objective resin.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a method for producing polyurethane resin.

<Prior Art> A polyurethane resin made by reacting a polyester diol obtained by polycondensing neopentyl glycol with adipic acid and diphenylmethane diisocyanate is well known.

<Problems to be Solved by the Invention> However, the above-mentioned polyurethane resins have a drawback in that solid dispersibility (for example, dispersibility of pigments and magnetic powders) is insufficient.

<Means for Solving the Problems> In view of the above circumstances, the present inventors conducted extensive studies to obtain a polyurethane resin with excellent solid dispersibility, and found that a glycol having two or more side chains of alkyl groups, Furthermore, it has been found that a glycol in which at least one of the alkyl groups is an alkyl group having 2 or more carbon atoms or has 3 or more methyl groups is used as a component for producing a polyurethane resin and has excellent solid dispersibility. The present invention has now been completed.

That is, the present invention provides a method for producing a polyurethane resin in which a diol and a diisocyanate are reacted, wherein the diol is a glycol having two or more alkyl group side chains, and at least one of the alkyl groups has two or more carbon atoms. A method for producing a polyurethane resin, characterized by using a glycol (A) having an alkyl group or three or more methyl groups, or a polyester diol consisting of the glycol (A) and a dicarboxylic acid (B), and a terminal thereof. In a method for producing a polyurethane resin in which a urethane prepolymer having isocyanate groups is reacted with a chain extender, the urethane prepolymer is a glycol having two or more side chains of alkyl groups, and at least one of the alkyl groups is carbon. Using a urethane prepolymer made by reacting a polyester diol consisting of a glycol (A) which is an alkyl group having two or more atoms or has three or more methyl groups and a dicarboxylic acid (B) and a diisocyanate (C). The present invention provides a method for producing a polyurethane resin characterized by the following.

The method for producing a polyurethane resin of the present invention includes: (1) a method of reacting a diol and a diisocyanate to produce a polyurethane resin; (2) reacting a diol and a diisocyanate in advance to obtain a urethane prepolymer with terminal isocyanate groups; There is a method of producing a polyurethane resin by reacting this with a chain extender (hereinafter referred to as method (1) and method (2), respectively).

Gelcol (A) according to the present invention, which is a glycol having two or more alkyl group side chains, and at least one of the alkyl groups is an alkyl group having two or more carbon atoms, or has three or more methyl groups [ Below, simply glycol (
A). ] is a glycol having two or more alkyl group side chains, and at least one of the alkyl groups is an alkyl group having 2 or more carbon atoms (A
1), a glycol having two or more alkyl group side chains, and a glycol having three or more methyl groups (
A-2). Hereinafter, they will be referred to as glycol (A-1) and glycol (A2), respectively. ] As the glycol (A-1), for example, 2-ethyl-1
, 3-hexanediol, 2,2-diethyl-1,3-
Propanediol, 2-methyl-2-ethyl-1,3-
Propanediol, 2-methyl-2propyl-1,3-
Propanediol, 2-methyl-2-butyl-1,3-
Examples of the glycol (A2) include propanediol, 2,2-diprobyl-1,3-propanediol, 2,2 dibutyl-1,3-propanediol, and 2-butyl 1,3-hexanediol; .4-) riftyl-1,3-pentanediol, 2,2,4-trimethyl-1,4-bentanediol, etc., and these may be used alone or in combination of two or more types.

Usually, glycol (A) is used after dehydration condensation with dicarboxylic acid (B) to form polyester diol.

The method for obtaining polyester diol by condensing glycol (A) and dicarboxylic acid (B) is not particularly limited, and any known and commonly used method can be employed.

Examples of the dicarboxylic acid (B) used in this case include succinic acid, adipic acid, azelaic acid, sebacic acid,
Dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1
, 3-cyclopenkune dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, Naphthalic acid, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid and anhydrides or ester-forming derivatives of these dicarboxylic acids; p-hydroxybenzoic acid, p-(2hydroxyethoxy) Mention may be made of benzoic acid and ester-forming derivatives of these hydroxycarboxylic acids.

When using the glycol (A) as a polyester diol made by reacting with a dicarboxylic acid (B), a polyester diol having a hydroxyl equivalent of 200 to 3000 is used because the final polyurethane resin has excellent water resistance and solid dispersibility. It is preferable to use it as

The polyester diol may be produced only from glycol (A) and dicarboxylic acid (B), but glycols other than glycol (A) may be used as necessary.

Examples of glycols other than glycol (A) include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 15-bentanediol, 3-methyl 1,5-bentanediol,
1.6-hexanediol, neopentyl glycol,
Diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bisphenoloxybenzene, 1,4-cyclohexanediol, 4-cyclohexane dimetatool, bisphenol A, hydrogenated bisphenol A, hydroquinone and Examples include glycols such as alkylene oxide adducts thereof.

In the present invention, sufficient solid dispersibility can be obtained by using glycol (A), but if even higher solid dispersibility is required, a compound containing a hydrophilic group and an active hydrogen atom may be used. is preferably used in combination with glycol (A).

Examples of compounds containing a hydrophilic group and an active hydrogen atom include 2-oxyethanesulfonic acid, phenolsulfonic acid, sulfobenzoic acid, sulfosuccinic acid, 5-sulfoisophthalic acid, and 5-sulfobis(β-hydroxyethyl)isophthalate. , sulfanilic acid, ■, 3-phenylenediamine-4,6-disulfonic acid, 2,4-diaminotoluene-5-sulfonic acid and other sulfonic acid-containing compounds and their derivatives 2.2-dimethylolpropionic acid, 2,
2-dimethylolacetic acid, 2.2-dimethylolvaleric acid, dioxymaleic acid, 2.6-dioxybenzoic acid, 3.4
-carboxylic acid-containing compounds such as diaminobenzoic acid, N-t
Examples thereof include tertiary amino group-containing compounds such as -butylgetanolamine, N-ethylgetanolamine, diisopropyl-N, and N' (2-hydroxyethylaminomethyl)phosphonate.

Furthermore, if necessary, monocarboxylic acid, monoalcohol,
A trifunctional or higher functional carboxylic acid or alcohol may be used in combination.

When using a glycol other than glycol (A) when producing the polyester diol described above, the glycol (A) is 50 parts by weight or more when the total of glycol (A) and other glycols is 100 parts by weight. It is preferable to use it so that

Glycol (A) can of course be used not only as a polyester diol (but also as a raw material for the polyurethane resin described later).

Methods (1) and (2) for producing a polyurethane resin of the present invention will be sequentially explained.

Method (2) of the present invention is a method in which glycol (A) or polyester diol of glycol (A) and dicarboxylic acid (B) is reacted with diisocyanate (C) described below.

In this urethanization reaction, the ratio of active hydrogen groups to isocyanate groups is usually 0.5:1.0 to 0.98:1.0.
The reaction is carried out at 20 to 120°C, preferably 30 to 100°C, using a catalyst if necessary. Examples of the diisocyanate (C) include 2.4-1-lylene diisocyanate, 2.6-1-lylene diisocyanate, m-
Fuynylene diisocyanate, p-Fyynylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4' diphenylmethane diisocyanate, 2,
2'-diphenylmethane diisocyanate, 3,3'-
dimethyl-4,4'-biphenylene diisocyanate,
3.3'-dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, tetramethylene diisocyanate , ■, 6-hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate,
■, 3-cyclohexylene diisocyanate, l, 4-
Cyclohexylylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, 4.4'~
Dicyclohexylmethane diisocyanate, 3,3'-
Examples include dimethyl-4,4'-dicyclohexylmethane diisocyanate.

The above reaction can be carried out without a solvent, but an organic solvent can also be used for the purpose of controlling the reaction or reducing the viscosity of the reaction system.

Such organic solvents are not particularly limited, but include, for example, aromatic hydrocarbons such as toluene and xylene; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; acetate esters such as ethyl acetate and butyl acetate; dimethylformamide, Examples include amine Fs such as N-methylpyrrolidone.

As the catalyst, any known and commonly used catalyst can be used, and examples thereof include organometallic catalysts such as stannous caprylate and dibutyltin diamine, and tertiary amine catalysts such as tetramethylbutanediamine, triethylamine, and trimethylamine. It will be done.

In the method (2) of the present invention, glycol (A) or polyester diol obtained from glycol (A) and dicarboxylic acid (B) may be used alone, but other diols may be used in combination.

Examples of diols that can be used in this case include polyether polyols, polycarbonate polyols, polyacetal polyols, polyacrylate polyols, polyesteramide polyols, and polythioether polyols.

Examples of polyether diol include ethylene glycol,
Diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1.3-
Butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane, sorbitol, sucrose, aconite sugar, trimellitic acid,
Hemimellitic acid, phosphoric acid, ethylenediamine, diethylenetriamine, triisopropanolamine, pyrogallol, dihydroxybenzoic acid, hydroxyphthal s, 1
Ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, cyclohexylene, using as an initiator one or more compounds having at least two active hydrogen atoms such as , 2.3-propane trithiol, etc.
Examples include those obtained by addition polymerization of one or more of the following monomers by a conventional method.

Examples of the polycarbonate diol include compounds obtained by reacting glycols such as 1.4-butanediol, 1,6-hexanediol, and diethylene glycol with diphenyl carbonate and phosgene.

Furthermore, if necessary, polyhydroxy compounds such as glycerin, trimethylolethane, trimethylolpropane, sorbitol, and pentaerythritol; ethylenediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine , 4,4'-dicyclohexylmethanediamine, 33'
-Dimethyl 4,4'-dicyclohexylmethanediamine, 1,4-cyclohexanediamine, 1,2-propanediamine, hydrazine, diethylenetriamine, triethylenetetramine, acid hydrazide, and other amine compounds may be used in combination.

The production method (2) of the present invention is a method in which a urethane prepolymer having terminal isocyanate groups is produced in advance, and this is reacted with a chain extender having an active hydrogen atom.

The method for producing the urethane prepolymer with terminal isocyanate groups used in this case is not particularly limited (e.g., polyester diol obtained from glycol (A) or glycol and dicarboxylic acid (B) and diisocyanate are prepared in excess of diisocyanate). More specifically, the equivalent ratio of isocyanate groups to active hydrogen groups is 1.1:1.
The reaction may be carried out at a ratio of ~3:1, preferably 1.2:1 to 2:1, and the other urethanization conditions may be those of the production method (2) above.

A polyurethane resin is produced by reacting the above-mentioned urethane prepolymer having terminal isocyanate groups with a chain extender having an active hydrogen atom.

The amount of the chain extender used in the method of the present invention (2) is not particularly limited, but the equivalent ratio is usually 0.5:1 to 1:1 to the isocyanate group in the urethane prepolymer.
1, preferably in an amount of 0.6:1 to 0.98:1. As other conditions for reacting the urethane prepolymer and the chain extender, the conditions in the production method (2) above can be employed.

Examples of chain extenders that can be used in this case include glycols other than glycol (A) that can be used in the production of polyester diol in the production method (1) above, and compounds containing hydrophilic groups and active hydrogen atoms such as amine compounds. can also be used.

The polyurethane resins obtained by the production methods (1) and (2) of the present invention have a number average molecular weight of 5,000 to 100,000, particularly 8,000 to 500' because they have good mechanical properties, excellent water resistance, and excellent solid dispersibility. 00 is preferred.

The polyurethane resin obtained by the production method of the present invention may contain other resins, antioxidants, ultraviolet absorbers, hydrolysis inhibitors, pigments, dyes, thickeners, antifoaming agents, surfactants, etc., as necessary. Agents, antistatic agents, flame retardants, deodorants, dispersants, tackifier resins, fillers, crosslinking agents, magnetic powders, etc. can be added.

In addition, in the present invention, in addition to the polyurethane resin, other commonly used resins may be used, if necessary, such as polyurethane resins, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl propionate copolymers, and polyvinyl butyral copolymers. Commercial products such as resins, cellulose resins, polyester resins, epoxy resins, phenoxy resins, and polyamide resins can also be used in combination.

Examples of the crosslinking agent include phenol-formaldehyde resin, urea-formaldehyde resin, melamine-formaldehyde resin, and organic polyisocyanate.

Preferred crosslinking agents include the organic diisocyanates used in producing the polyurethane resin composition, their polymers, and polyisocyanates in which bifunctional or more functional polyols are terminally isocyanate groups with the organic diisocyanates, and the functional groups of these polyisocyanates. Blocked isocyanates with blocked groups are suitable. The number average molecular weight of these polyisocyanates is preferably from 160 to 2,000, such as Crisbo:/NX, CL-2.
, CL-5O3, Parnock D-750, DN-950
, D-500, D-550C or higher, Dainippon Ink & Chemicals Product], Desmodule L, R, RF C or higher,
Any commercially available products from various companies, such as Sumitomo Bayer Urethane ■Products, can be used.

Examples of magnetic powder include reduced iron powder, T-Fe20.
Powder, Fe50. Powder, Co-containing r-Fe, O, powder,
Examples include Co-containing Fe:+04 powder, CrO□ powder, and various conventionally known magnetic powders can be used.

The polyurethane resin composition of the present invention can be used in various applications such as adhesives, paints, fiber treatment agents, molding materials, raw materials for synthetic leather, and binders for magnetic recording media.

<Example> Next, the present invention will be explained by examples.

Note that all "parts" below are based on weight.

#*Jl-5 (Synthesis of polyester diol) Glycols and dicarboxylic acids shown in Table 1 were dehydrated and condensed according to a conventional method to obtain various polyester diols having the properties shown in the table.

/ Examples 1 to 2 and Comparative Example 1 Table 1 Reference Examples 1.3 and 5 polyester diol a,
C and e were dissolved in dimethylformamide, diphenylmethane diisocyanate was charged all at once, and the mixture was reacted at 80° C. for 5 hours to obtain a urethane prepolymer having terminal isocyanate groups.

This urethane prepolymer with terminal isocyanate groups has 1
, 4-butanediol were charged all at once and reacted at 70°C for 10 hours to obtain a polyurethane resin. If necessary, add more dimethylformamide to bring the solid content concentration to 30%.
It was adjusted to

The pigment dispersion stability of the polyurethane resin solution thus obtained, the glossiness of the pigmented film, and the retention rate of film physical properties after exposure to artificial juice were measured.

These results are summarized in Table 2.

The above physical properties were measured as follows.

*l) Pigment dispersion stability A sample consisting of the following formulation was weighed into a 200 mf glass container, and stirred and mixed at 800 rpm for 10 minutes to prepare a colorant-containing polyurethane resin solution.

100 parts of urethane resin solution 40 parts of methyl ethyl ketone 20 parts of this product were allowed to stand in an atmosphere at 2° C. for 5 days, and separation and sedimentation phenomena of the pigment in the polyurethane resin solution were observed.

Book 2) Glossiness of Pigment Colored Film The colored solution of Book 1) was applied onto a polyester film and dried with hot air at 80°C for 5 minutes to obtain a film with a thickness of about 30 μm.

The 60° glossiness of this product was measured using a gloss meter manufactured by Nippon Shokuhika Kogyo ■.

Book 3) Retention of physical properties of film after exposure to artificial juice The following formulation (crosslinking agent and crosslinking accelerator was added to the urethane resin solution to make a homogeneous solution was applied onto release paper and dried with hot air at 80°C for 5 minutes. A transparent film with a thickness of about 30 μm was obtained.

Urethane resin solution Chrisbon NX 100 parts 65 parts Chrisbon Accel HM Part a Next, 25 parts of glacial acetic acid, 40 parts of disodium hydrogen phosphate dodecahydrate,
40 parts of sodium chloride and 895 parts of water were uniformly mixed to obtain an artificial juice liquid.

7. Hang the film in an airtight container with artificial juice at the bottom.
It was exposed for 5 days at 0°C, then thoroughly washed with water and air-dried.

This film was cut into 5 wa x 4 Q w, and changes in strength and elongation were measured using an autograph manufactured by Shimadzu Corporation under conditions of a tension interval of 20 mm and a tension speed of 300 w10+in.

This physical property retention rate is a measure of hydrolysis resistance.

Examples 3 to 4 and Comparative Example 2 Various polyurethane resins were obtained by performing exactly the same operations as in Example 1 except for using the raw materials shown in Table 3.

Next, a test exactly the same as in Example 1 was conducted.

The results are shown in Table 3. Solid content concentration is also 3
It was adjusted to 0%.

However, as the organic solvent, a mixed solvent of toluene and isopropanol in a weight ratio of 1:1 was used.

/ and r' and Examples 5 to 8 and Comparative Example 3 Various polyurethane resins were obtained by performing the same operations as in Example 1 except for using the raw materials shown in Table 4. If necessary, add more methyl ethyl ketone to bring the solid concentration to 40.
%.

The magnetic powder dispersion stability of the polyurethane resin solution thus obtained and the glossiness of the magnetic paint film were measured.

These results are summarized in Table 4.

The above physical properties were measured as follows.

Rate 4) [Size powder dispersion stability 500mj! A sample consisting of the following formulation was placed in a ball mill, mixed and dispersed for 10 hours, and then filtered through a filter to obtain a magnetic paint.

r-Fez03 (He:6760e.

Various urethane resin solutions Methyl ethyl ketone Toluene Microhexanone BET 31-9m''/gr) 80 parts 50 parts 30 parts 100 parts 100 parts 20 parts of this magnetic paint were left to stand in an atmosphere at 2°C for 1 day.
Separation and sedimentation phenomena of magnetic powder were observed.

Book 5) Glossiness of Magnetic Paint Film The magnetic paint from Book 4) was applied onto a polyester film and dried with hot air at 80°C for 5 minutes to obtain a magnetic paint film of about 30 μm. The glossiness of this film was measured using a GM26D surface gloss meter from Murakami Color Research Institute. Note that the reflectance at an incident angle of 60° and a reflection angle of 60° was used as the glossiness.

The polyurethane resin of Example 1.2 was particularly suitable for use in synthetic leather/artificial leather, that of Example 3.4 was particularly suitable for use in gravure printing ink, and that of Examples 5 to 8 was particularly suitable for use in magnetic recording media. .

〔Effect of the invention〕

The polyurethane resin obtained by the production method of the present invention has excellent dispersion stability of solids such as pigments and magnetic powders compared to conventional polyurethane resins, and a polyurethane resin film with high gloss can be obtained.

Therefore, the polyurethane resin obtained by the production method of the present invention can be used as a raw material for synthetic leather/artificial leather, a printing ink vehicle,
It is particularly useful as a magnetic recording media binder.

Claims (1)

[Claims] 1. A method for producing a polyurethane resin in which a diol and a diisocyanate are reacted, wherein the diol is a glycol having two or more alkyl group side chains, and at least one of the alkyl groups is carbon. A polyurethane resin characterized by using a glycol (A) which is an alkyl group having two or more atoms or has three or more methyl groups, or a polyester diol consisting of the glycol (A) and a dicarboxylic acid (B). Production method. 2. A urethane prepolymer with terminal isocyanate groups,
In a method for producing a polyurethane resin that involves reacting with a chain extender, the urethane prepolymer is a glycol having two or more alkyl group side chains, and at least one of the alkyl groups is an alkyl group having 2 or more carbon atoms. Glycol (A
) and a dicarboxylic acid (B), and a diisocyanate (C).