JPS60149624A - Thermoplastic polyurethane resin - Google Patents

Abstract

PURPOSE:The titled resin soluble in a general-purpose organic solvent and excellent in toughness, abrasion resistance, etc., prepared by using a long-chain diol, a short chain diol containing a branched diol, an organic diisocyanate and an isocyanurate ring-containing triisocyanate. CONSTITUTION:A thermoplastic polyurethane resin of a MW>=8,000 prepared by reacting (A) a long-chain diol of a MW of 500-5,000wt% short-chain diol having an alkyl group as a side chain, (C) an organic diisocyanate and (D) an isocyanurate ring-containing triisocyanate at a reactant ratio satisfying relationships I , II, and III (wherein a, b, c, and d are the numbers of moles of components A, B, C, and D, respectively). This polyurethane resin is soluble in a solvent such as methyl ethyl ketone, ethyl acetate or toluene and excellent in mechanical properties such as toughness and abrasion resistance, and has a long pot life and excellent curability when used in a two-component formulation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoplastic polyurethane resin, more specifically, it is soluble in a general-purpose solvent and has excellent mechanical properties.

To provide a thermoplastic polyurethane resin which can provide a polyurethane resin having excellent heat resistance and solvent resistance when cured into a three-dimensional network shape, and is particularly suitable for the fields of paints, coating agents, adhesives, etc.

Polyurethane resins have excellent physical properties such as toughness and abrasion resistance that are unique to polyurethane resins due to intermolecular hydrogen bonds formed by urethane bonds. However, increasing the urethane group concentration lowers the solubility in general-purpose organic solvents. In other words, are conventional thermoplastic polyurethane resins insoluble in general-purpose organic solvents?1. Many of them are soluble only in highly polar, high-boiling solvents such as dimethylsulfamide, N-methylpyrrolidone, dimethylsulfamide, and cyclohexane, and cyclic ethers such as tetrahydrofuran and dioxane, and are used as such solvents. In this case, there are problems such as a decrease in workability and swelling or dissolution of the material to be coated.

In addition, the heat resistance of high molecular weight thermoplastic polyurethane resin,
In order to improve solvent resistance etc., a so-called two-component method is known in which a curing reaction is carried out using a polyisocyanate compound in the case of a hydroxyl-terminated thermoplastic polyurethane resin, and a polyol compound in the case of an isocyanate-terminated thermoplastic polyurethane resin. It is being

However, in the case of conventional thermoplastic polyurethane resins having terminal groups as crosslinking points, crosslinking through urethane bonds does not provide sufficient improvement in heat resistance or solvent resistance because the crosslinking density is low. Further, crosslinking by allophanatization reaction, which is a reaction between a urethane bond and an isocyanate group, has the drawback of requiring high temperatures.

In order to improve the crosslinking density of the cured product obtained by the two-component method,
It is known to use a branched polyurethane resin by using a trifunctional or higher functional polyol component such as trimethylolpropane (TMP) or pentaerythol as part of the raw materials for the polyurethane resin. This method No. 9 has disadvantages in that the solubility of the polyurethane resin in general-purpose solvents decreases or becomes insolubilized due to the amount of trifunctional or higher polyol components used, and the pot life in the two-component state decreases.

The present inventors have achieved the present invention as a result of intensive research in order to solve the above-mentioned drawbacks and develop a thermoplastic polyurethane resin having the characteristics shown below.

■Methyl ethyl ketone, methyl isobutyl ketone 7, ff
14jf2xt&, vinegar e cellulosolve, toluene l
It is soluble in at least a primary solvent selected from xylene and the like.

■Excellent mechanical properties such as toughness and wear resistance.

■When used in the two-component method, it has a long pot life and excellent curing properties.

The object of the present invention is long chain diols and short chain diols.

It has been found that this can be achieved by using an isocyanurate ring-containing triisocyanate together with an organic diisocyanate, and by using a branched short-chain diol as the short-chain di-)v within a specific range. That is, the present invention has a molecular weight of 5.
Thermoplastics obtained from long-chain di-/I/(A) with a molecular weight of 0 to 5000, short-chain di-/' with a molecular weight of less than 500 (B) 1 organic diisocyanate CC) and isocyanurate ring-containing triisocyanate (D,) A polyurethane resin, in which component (B) contains a short chain diol having an alkyl group in the side chain in an amount of 30 to 100% based on the total weight of component (B).
Weight - including (A), (B), (C) and (
D) A thermoplastic polyurethane resin having a molecular weight of 8,000 or more is formed by reacting the components in the following proportions.

(1) 1≦-≦5 (1) 5x 10-3≦Work≦I The number of moles, b is the number of moles of component (B), C is the number of moles of component (C), and d is the number of moles of component (■). ) In the present invention, -m,! of the polyisocyanate raw material.
: Contains an isocyanurate ring! By using J isocyanate within a specific range, a thermoplastic polyurethane resin with excellent curability can be obtained without significantly shortening the pot life in the two-component method. Even if this isocyanurate ring-containing triisocyanate is replaced with another trifunctional raw material, such as trimethylolpropane or a 1:3 adduct of trimethylolpropane and tolylene diisocyanate, the effects found in the present invention are not obtained.

The long chain di-/l/(A) used in the present invention has a molecular weight in the range of 500 to 5000, and the polyester di-/l/(A) has a molecular weight in the range of 500 to 5000, and
I/, polyether diol, polycarbonate diol and the like. The carboxylic acid component of polyester diol includes aromatic dicarboxylic acids such as themphthalic acid, isophthalic acid, orphthalic acid, and 1,5-naphthalic acid;
Examples include aromatic oxycarboxylic acids such as β-oxybenzoic acid and p-<hydroxyethoxy)benzoic acid, and aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid. Particularly preferred are terephthalic acid, isophthalic acid, adipic acid, and sebacic acid. In addition, the glycol components of polyester diol include ethylene glycol/l/, propylene glycol/I/, R3-propanediol, 1,4-
Butanediol, 1,5-bentanediol, 1,6-
Hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 2,2.4-
) Dimethyl-1,3-pentanedio/I/, cyclohexanedimethanol=A/, ethylene oxide adduct and propylene oxide adduct of bisphenol A,
Examples include ethylene oxide adducts and propylene oxide adducts of hydrogenated bisphenol/l/A, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

As a raw material component of polyester diol other than the above, 5
- Ester-forming compounds containing sulfonic acid metal bases such as sodium sulfoiphthalic acid, 5-potassium sulfoiphthalic acid, and sodium sulfoterephthalic acid, and phosphorus-containing ester-forming compounds represented by the following general formulas CI) and (II) Is it polyvarnish, te, ludiol, which is a copolymerized compound? It's okay.

(In the formula, R is a monovalent ester-forming functional group.

R2+ R3 are the same or different groups, and include a monovalent hydrocarbon group having 1 to 10 carbon atoms, a halogen atom, and 1
selected from the group consisting of valent ester-forming functional groups. X
represents a divalent or trivalent organic residue. Also, tnl is 1
or 2+12+n3 each represents O or an integer from 1 to 4) (In the formula, R4 represents a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms that may contain an ester-forming functional group, and M2゜R5 represents carbon A divalent or trivalent hydrocarbon group having 1 to 6 atoms. R6 is a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may contain a hydroxyl group, or M3゜MIIM21M3
is an alkali metal atom.

(m is 0 or an integer of 1, 1 or t/i2) The adjoining compound represented by the general formula [:I], , (II] is a compound containing a sulfonic acid metal base as a starting material, !:
4) The thermoplastic polyurethane resin using polyester diol obtained as a component is an inorganic pigment found in conventionally known thermoplastic polyurethane resins.

It is effective in significantly improving the drawback of low dispersibility of fillers, etc.

As polyether diol, polyethylene glycol
/L/, polyalkylene glycols such as polypropylene glycol and polytetramethylene glycol. As polycarbonate diol, the general formula H+
It is a long chain diol represented by 0-R-OCO-)nROH, where R is diethylene glyco-71/, 1.6
-hexanediol, bisphenol A, etc.

The long chain diol (A) used in the present invention has a molecular weight of 50
Use a number between 0 and 5000. If the molecular weight is less than 500, the concentration of ureno groups becomes too thick, and the flexibility and solvent solubility of the resin decrease. Furthermore, if the molecular weight exceeds 5,000, the urethane group concentration decreases, and the toughness, abrasion resistance, etc. characteristic of polyurethane resins decrease.

The short chain diol (B) used in the present invention has a molecular weight of 50
less than 0, ethylene glycol, 113-furopylene gelicol, 1,4-tetradatilene gelicol/I/
, 1,6-hexanediol, cyclohexane dimetatool, xylylene diglycol.

Direct glycols such as ethylene oxide adducts of bisphenol A, propylene glycol/L/l neopentyl glycol, 1,2-butanediol, 1,3-butanediol, 2.2.4-trimethyl-1,3- Examples include branched glycols such as propylene oxide adducts of pentanedio-/L/, bispheno-/L/A, neobentyl hydroxypivalate, and stearic acid monoglyceride.

Short chain diols (B) other than those mentioned above can be expressed by the following general formula (N
) are phosphorus-containing compounds.

(In the formula, R7+R8 represents a monovalent hydrocarbon group and may be the same or different groups. Ro + Rso is a substituted or unsubstituted divalent alkylene group, oxyy tv
It is a polyoxyalkylene group spanning the ky group, and may be the same or different groups.

Y and Z represent a hydroxyl group when R91R10 is an alkylene group, and a hydrogen atom when Re +R+o is an oxyalkylene group or a polyoxyalkylene group. ) General formula (II) is used as a raw material for thermoplastic polyurethane resin.
When the phosphorus-containing compound shown in I) is used, it is effective in improving the low partitioning ability of inorganic pigments, fillers, etc., which is a drawback of conventional polyurethane resins.

In the present invention, the branched glycol of the short chain di-1v (B) component is
Use 100% by weight. Although it depends on the method for producing the thermoplastic polyurethane resin, the ratio of short-chain diols, etc., if the diol having a side chain delkyl group is less than 30% by weight, the solubility decreases.

As the organic diisocyanate (C) used in the present invention,
2,4-tolylene diisocyanate), 2,6-tolylene diisocyanate, p-phenylene diisocyanate,
diphenylmethane diisocyanate, m-phenylene diisocyanate, hexamethylene diisocyanate, 3
．． 3'-dimethoxy-4,4'-biphenylene diisocyanate, 2,4-1-phthalene diisocyanate, tetramethylene diisocyanate, '3,31-dimethylene w
-4,4'-biphenylene diisocyanate, 4.
4'-diphenylene diisocyanate, 4.4'-diisocyanate diphenylethe/L'1l15-naphthalene diisocyanate, p-xylylene diisocyanate, m-'f silylene diisocyanate, 1,3-diisocyanate methylcyclohexane, 1,4-diisocyanate methyl Cyclohexane, 4,4'-diisocyanate dicyclohexane, 4,4'-diisocyanate dicyclohexylmethane, inphorone diisocyanate, etc. are used.

Examples of the isocyanurate e-containing triisocyanate used in the present invention include Vi, a trimer of top organic diisocyanate, or a polymer of the trimer. Examples include the following:

H3 As a short chain diol having an alkyl group in the side chain used as a raw material for the thermoplastic polyurethane resin of the present invention, H,
1,2-propylene glyco-/'1113-butanediol, neopentyl glycol, bispheno-/l/A
Examples include ethylene oxide adducts and propylene oxide adducts. 'The resin is a long chain di-/'(A) with a molecular weight of 500 to 5000.
.

Short-chain diisocyanate (C) and incyanurate ring-containing triisonane (B) with a molecular weight of less than 500, CD), when the number of moles of each component is a, b%C and d, (1) 1≦-≦5 (&) 5X10-3≦□≦I . If - exceeds 5, the solubility in general-purpose solvents will decrease, and if b - is less than 1, the toughness characteristic of polyurethane resins will decrease, making it impossible to achieve the object of the present invention.

. +6 is X of the incyanurate ring-containing triisocyanate in the incyanate component; if it is less than 10-3, the effect of using the incyanurate ring-containing triisocyanate is no longer seen.

Definitely. - If "-" is less than 1, the isocyanate terminal c
+d It becomes a polyurethane resin and hardens with moisture. In the present invention, from the viewpoint of storage stability in the solution state a+b. and is preferably 1 or more.

Methods for producing thermoplastic polyurethane resins include the one-shot method in which all di-μ components and all incyanate components are reacted simultaneously, and the incyanate-terminated prepolymer obtained by mulling long-chain diol and incyanate components. There is a prepolymer method in which the chain is extended with a short chain diol. In the present invention, in both the one-shot method and the prepolymer method, especially organic diisocyanates with 70%
It is preferable to add the incyanurate ring-containing triisocyanate at the stage where % or more of the incyanurate ring-containing triisocyanate has reacted. When the incyanurate ring-containing triisocyanate is added during a reaction in which the organic diisocyanate content is less than 70%, gelation may occur if the amount of the incyanurate ring-containing triisocyanate used is large.

Thermoplastic polyurethane resins can be produced by methods such as molten raw materials or dissolving them in a solvent. In the present invention, the entire reaction can be carried out alone or in a mixed solvent such as methyl ethyl ketone, toluene, ethyl acetate, etc. Preferred methods include methods in which the prepolymer is prepared in a molten state and the chain extension reaction is performed in a solvent. The molecular weight of the thermoplastic polyurethane resin needs to be 8000 or more in view of mechanical properties such as toughness and abrasion resistance.

When producing a thermoplastic polyurethane resin, stannous octylate, digtyltin dilaurate, triethylamine, etc. may be used as a reaction catalyst. Also.

Ultraviolet absorbers, hydrolysis inhibitors, antioxidants, gas yellowing inhibitors, colorants, inorganic fine particles, metal soaps, organopolysiloxanes, perfluoroalkyl group-containing mold release agents, and other additives are added to thermoplastic bipolyurethane resins. Added before, during or after manufacturing.

You may.

The thermoplastic polyurethane resin thus obtained is suitable for use in paints, coating agents, adhesives, etc., and is also useful as a fiber treatment agent, magnetic binder, etc.

Hereinafter, the present invention will be specifically explained with reference to Examples.

In addition, in the examples, the term "parts" does not indicate parts by weight.

<Production Example of Polyester Resin> 175 parts of dimethy/L/terephthalate was placed in a reaction vessel equipped with a thermometer, a stirrer, and a partial reflux condenser.

78 parts of dimethyl isophthalate, ethylene glycol/l
/161 parts, -neopentyl glyco-/L' 145 parts.

5-sodium; and dimethyl rufoisophtabylate 1v14.
Add 8 parts and 0.2 parts of tetrabutyl titanate to 11
Transesterification reaction was carried out at 40-220°C for 4 hours. Next, 131 parts of sepacic acid was added, and the mixture was heated at 210 to 230°C for 1
After reacting for an hour, polycondensation reaction was carried out at 230° C. for 20 minutes while reducing the pressure of the reaction system to 1 to 0.2 Hf. The obtained polyester diol (A-1) was obtained by terminal titration method, N
From analysis such as MR, 1 molecular weight f'i2. OOO, acid value 0.
2 KOH'W/f, the composition was as follows.

Terephthalic acid 45 mol Isophthalic acid 20 Sepacic acid 32.5 5-Sodium sulfoisophthalic acid 25 Ethylene glyco=A150 Neopentyl glycol 50 Polyester diols (A-2) to (A- Example 1: 172 parts of toluene, 172 parts of methyl ethyl ketone, 100 parts of polyester di-/L/(A-1) and neopentyl were placed in a reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser. Prepare 10 parts of glycol.

After dissolving 4.4'-diphenylmethane diisocyanate 3
After adding 0.02 parts of Djibouti/L/@dilaurate and reacting at 70 to 75°C for 60 minutes, Coronate 2
Add 10 parts of 030 (manufactured by Nippon Polyurethane Co., Ltd., a 50% solution of Torun diisocyanate trimer) and further heat to 75°C.
The mixture was allowed to react for 10 hours.

The obtained polyurethane resin (U-1) solution has a solution viscosity of 3
It was a pale yellow, transparent solution at 0 poise/25° C. and a solid content concentration of 30% by weight. In addition, analysis by gel permeation chromatography (G, P, C) showed that the molecular weight of the polyurethane resin was 18,000.

Examples 2 to 6, Comparative Examples 1 to 9 Polyurethane resins (U-2) to (U-1,4) shown in Table 2 were obtained in the same manner as in Example 1. Among the comparative examples, Comparative Example 1 is a resin containing no isocyanurate ring-containing triisocyanate, and Comparative Examples 2 and 3 are resins in which the incyanurate ring-containing triisocyanate is 5 X 10-3≦-d-≧I
It is a c+d resin that does not satisfy the range of X 10-1. Comparative Example 4.5 uses incyanurate ring-unmerited triisocyanate and TMP()rimethylolpropane). In addition, Comparative Examples 6 and 7 are outside the range of 1≦silence≦5, and Comparative Example 6 of 1 is extremely low in breaking strength as shown in the resin properties in Table 2. It does not have the desired toughness of polyurethane resin. In Comparative Example 7 of Example 5, the solution also became cloudy.

In Comparative Example 8, the amount of branched short-chain diol was less than 30% by weight as a short-chain diol component, resulting in a cloudy appearance.

In Comparative Example 9, the polyurethane resin has a molecular weight of less than 8000, and its resin properties are significantly lower than the toughness of the polyurethane resin targeted by the present invention.

(I) Curability and viscosity increase in solution A trifunctional incyanate compound (manufactured by Nippon Polyurethane Kogyo Co., Ltd., using Coronate L (TMP・[:TDI]s)) is solidified in the thermoplastic polyurethane resin solution shown in Table 2. Add 10 weight f1% in proportion, MEK/toluene = 1/
1 to adjust the solid content concentration to 15% by weight.

This solution was applied onto a polyester film so that the dry coating thickness was 10 μm, and after drying with hot air at 100° C. for 1 minute, it was left in an atmosphere of 50° C. and 40% RH for 1 day. The obtained polyester film was immersed in MEK for 1 hour, and the MEK insoluble content was measured by comparing the weight before and after immersion and after completely scraping off the coated layer. Also, said 1
Table 3 shows the measurement results of the change in solution viscosity over time of the 5% by weight solution at 20°C.

Table 3: Number of days it took for the viscosity of the solution to become three times its initial value Examples 1 to 6 had better curing properties than the comparative example, and there was almost no difference in solution storage stability. There wasn't.

(II) Abrasion resistance, a sample under the same conditions as the sample used for MEK insoluble content measurement in (1) using a taper tester ((11 film thickness is 50
The amount of wear (μm) was measured. The results are shown on the back-4.

Table 4 (II) Characteristics of coating film containing pigments and fillers ■Polyurethane resin/γ-FezOs/N agent (Coronate L)/ME
K/) Luene = 100/100/20/600/600 (weight ratio) ■Polyurethane resin/carbon black/curing agent (Coronate L)/MEK/toluene = 100/100/2
0/600/600 (weight ratio) The mixture was mixed in the ratio of (1) and (2) above, mixed in a ball mill for 10 hours, and then coated on a polyester film to a thickness of 10 μm.
After drying with hot air at 00°C for 1 minute, it was left in an atmosphere of 50°C and 80% RH for 1 day. Table 5 shows the measurement results of the curability and surface gloss of the resulting coating film.

Table 5 Mine 1) Number of times the coat layer is rubbed with a cotton swab soaked in MEK until the coat layer is completely rubbed off *2) Values measured with a gloss meter (data at an incident angle of 60 degrees) Table -5, it is clear that the Examples are superior to the Comparative Examples in terms of the curability of the coating film, and in terms of surface gloss, which is a measure of pigment dispersibility, the Examples containing polar groups showed high values. ing.

(N) Biaxially oriented polyethylene terephthalate with adhesion to polyester film of 50 μm. Film thickness after drying is 10 μm.
Apply it so that it becomes

After drying with hot air at 100°C for 3 minutes, place 1 on aluminum foil (15 μm).
It was crimped under the conditions of 20°C, 3 kg/crA, 5 sec, and left at 40°C for 3 days. The peel strength measurement results at 20°C and 100°C are shown in Table 6.

Table 6 Table 6 shows that the examples have better heat resistance than the comparative examples.

Example 7 In a reaction vessel similar to Example 1, 174 parts of toluene, 174 parts of methyl ethyl ketone, and polyester diol (A-
1) After charging and dissolving 100 parts of 4,4'-diphenylmethane diisocyanate and 4 parts of propylene glycol, 34 parts of 4,4'-diphenylmethane diisocyanate and 0.02 part of dibutyltin dilaure were added and reacted at 70 to 75°C for 60 minutes. 6 parts of hexanediol was added, and 30 minutes later, 5 parts of Coronate EH (manufactured by Nippon Polyurethane Kogyo Co., Ltd., a trimer of hexamethylene diisocyanate) was added, and the mixture was further reacted at 75°C for 10 hours. The obtained polyurethane resin (U-15) solution had a solution viscosity of 15 poise/25°C and a solid content concentration of 30% by weight.
It was a pale yellow, transparent solution. Molecule of polyurethane resin jl t/iG, P, C analysis shows 25.000
Met.

Example 8. Comparative Example 10.11 Polyurethane resin solutions (U-16) to (U-18) as shown in Table 7 were obtained in the same manner as in Example 7.

Comparative Examples 10 and 11 have poor transparency. The reason for this is that the short chain diol component having a side chain alkyl μ group is less than 30% by weight. .゛Table -7

Claims (1)

[Claims] Molecule m is 500 to 5000 f) Long chain dit-/v(A)
. A thermoplastic polyurethane resin obtained from a short-chain diol (B) having a molecular weight of less than 500, a diincyanate (C), and an isocyanurate ring-containing triisocyanate (D), the resin having an alkyl side chain as a component (B). 30 to 1 short chain diol having groups based on the total weight of component (B)
Contains oo% by weight, (A), (B), (C
A thermoplastic polyurethane resin having a molecular weight of 500 or more, which is obtained by reacting components ) and (D) in the following ratio. (1) 1 ≦-≦5 (1) 5xlO-3≦□≦I C is the number of moles of component (B), C is the number of moles of component (C), and d is the number of moles of component (D).)