JPS60104118A - Polyurethane composition suitable for enamel-tone artificial leather - Google Patents

Abstract

PURPOSE:To provide the titled composition capable of coating the surface of artificial leather with a film having excellent surface luster, transparency, flexural resistance, yellowing resistance, surface properties, and hot press resistance, by dissolving a polyurethane prepared from specific raw materials in a solvent having a specific composition. CONSTITUTION:A polyurethane is produced from (A) a polymeric diol having an average molecular weight of 1,500-3,000 and obtained by mixing (i) an ethylene glycol-based polyester diol and/or polytetramethylene glycol and (ii) 1,6-hexanediol polycarbonate at a weight ratio (i/ii) of (1-9)/1, (B) an alicyclic organic diisocyanate and (C) an alicyclic organic diamine, wherein at least one of the components B and C contains the group of formula. The molar ratio of the component B to the component A is 2.5-4. The objective composition can be produced by dissolving the polyurethane in a solvent composed of 40-85wt% THF and 60-15wt% composition composed mainly of an alcoholic compound.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyurethane composition that can provide an artificial leather with excellent performance when used as an enamel-like artificial leather. More specifically, when applied to the surface of artificial leather, it improves surface gloss and transparency, that is, enamel feeling, as well as flexibility, especially low temperature flexibility, light yellowing resistance, NOx gas yellowing resistance, and surface physical properties. , excellent heat and pressure resistance i1.
The present invention relates to a polyurethane composition capable of forming a surface coating layer with a glossy surface and a glossy surface being obtained without trouble when forming the surface coating layer.

A highly transparent polyurethane layer is applied to the surface of the artificial leather, which is conventionally made with enamel-like artificial leather.

Those with a glossy and smooth surface are used. Such enamel-like artificial leather ViiThe method used is to apply a polyurethane solution to a smooth metal surface, then laminate the artificial leather, evaporate the solvent of the polyurethane solution, and then peel it off from the metal surface. Commonly used polyurethanes have the disadvantage that they have poor releasability from metal surfaces, and a smooth and glossy polyurethane layer cannot necessarily be obtained. By increasing the amount of hard segments in polyurethane, a polyurethane with excellent metal releasability can be obtained, but in this case, a drawback arises in that the polyurethane has poor bending resistance. Furthermore, conventionally used polyurethane tends to yellow due to light or NOx gas, which greatly impairs the enamel feel.

Inventors? 'i1 As a result of research into polyurethane solutions that satisfy all of these many performance requirements, we have arrived at the present invention. That is, the present invention is based on the polyurethane solution that satisfies all of these many required performances. Synthesized from a cyclic organic diisocyanate and an alicyclic organic diamine, and having the following conditions (1), (■) and Qll) (1) The polymeric diol is (A) an ethylene glycol polyester diol and/a is pollinat 2
A combination diol of methylene glycol and (B) 1,6-hexanesiol polycarbonate diol,
and (A)/(BJ mixing ratio is 1/1 to 1/1 by weight)
It must be 9/1.

(I) At least one of the alicyclic organic diisocyanate and the alicyclic organic diamine has a molar ratio of (IIl) the alicyclic organic diisocyanate to the polymeric diol of 2.5 to 4.0. thing.

The polyurethane and the solvent for dissolving this polyurethane are characterized in that 40 to 85% by weight of the polyurethane is tetrahydrofuran and 60 to 15% by weight is a compound whose main component is an alcoholic compound. A polyurethane composition suitable for enamel-like artificial leather is used. By using such a polyurethane composition, it is possible to prevent peeling, and improve transparency and surface gloss.
Excellent K, excellent bending resistance when exposed to light, and excellent resistance to light and N (J
An enamel layer is obtained which is not yellowed by x gas. In addition, in the present invention, 3-iso'/7 natemef: 3
．． 5.5-) Limethyl cyclohexyl isocyanate (commonly known as isoisophorone diisocyanate) and 1-amino-3-aminomethyl-3,5,5-)rimeter 7-lilohexane (commonly known as inphorone diamine). There is.

Next, individual constituent elements of the present invention will be specifically explained.

First, the polymeric diol that is a component of the raw materials used to synthesize polyurethane, which is one of the components constituting the polyurethane composition of the present invention, is ethylene glycol-based polyester diol 1゜6-hexanethiol polycarbonate. It is a mixture of zimers. Enalene glycol thread yl? Examples of the polyester glycol include polyethylene adibenito glycol (PEA), polyethylene butylene adipate glycol (PEBA), and polyester glycol (PEBA).
),,! -' 1-noethylenehexylene a. ) heh
Toy +): I-ru (PEJiA), polyethylene propylene adipate glycol (PEPA), etc. Ethylene glycol-based polyenteno J
Diol (') 1. t; - Mixing ratio (A) of he*sandiol polycarbonate glycol (13)
/ (average weight ratio is 1/1 to 9/l, preferably 6/4 to 9/1, and the average molecular weight of the polymeric diol V) must be in the range of 1500 to 3000. These conditions apply to the present invention. If these conditions are satisfied, kc, 1: the solder metal 1fA@depression t'h will be good9, and the bending resistance, especially the low temperature 1Br release property will be good. Outside the above mixing ratio range -C. Metal peeling ¥4vi and bending resistant chair, 1 ton
is insufficient. In addition, for applications requiring hydrolysis resistance, ti. It is preferable to use polytetramethylene glycol instead of ethylene glycol-based polyester diol. Even when polytetramethylene glycol is used, polyurethane with excellent metal releasability and bending resistance can be obtained.
The mixing ratio of -hexanethiol polycarboy and -todiol is l/1 to 9/l, preferably 6/4 to 8/l.
/2, and the average molecular weight is 1500 to 3 IJ 0
Must be in the range 0.

If this range is multiplied, problems similar to those described above will occur. Note that in the present invention 1. There is no problem in using a small amount of other polymeric polyols.

The alicyclic diisocyanate required for the synthesis of the polyurethane that constitutes the polyurethane composition of the present invention is inphorone diincyanate.

Examples include dicyclohekiflumethane-4,4'-diisocyanate, inglopylidene chloride inanate, and the like. Further, examples of the alicyclic organic diamine used in the synthesis of the polyurethane constituting the polyurethane composition of the present invention include inphorone diamine and 4,4'-diaminodicyclohexylmethane.

Examples include cyclohexylene diamine, 4,4'-diamino-3'3'-dimethylcyclohexylmethane, and the like.

The enamel layer made of polyurethane obtained by replacing the alicyclic organic diisocyanate and the alicyclic organic diamine with an aliphatic one is significantly inferior in side heating properties and physical properties, and ′=l:l If an aromatic type material is used, the yellowing resistance to light and NOx gas will be significantly inferior.

In the polyurethane composition of the present invention, the alicyclic organic diincyanate and alicyclic organic diamine used in the synthesis of polyurethane must be used, as described above. That is, either the aliphatic 3J', I-group organic diisocyanate must be impolone diiso7anate, the alicyclic diamine must be inphorone diamine, or both must be isophorone-based compounds. . In particular, it is preferable to use inphorone diincyanate and inphorone diamine together.
It is preferable to use inphorondiamine in combination with

In the case of hardness, the resulting polyurethane has good solution stability in a bath agent, that is, it is less likely to thicken over time or cause gelation.

Moreover, the surface physical properties of the enamel sea bream artificial leather obtained using this polyurethane are good, and the heat and pressure resistance is also good. Of course, negative effects caused by light and NOx gas are also not recognized.

Note that 1 the alicyclic organic diiso 7 for the polymer diol
The molar ratio of anate is necessarily 2.5 to 4.0, preferably 2.7 to 3.7. 2.5
If it is less than 4.0, not only the whole area releasability will be poor, but also the heat and pressure resistance 1 surface physical properties will be poor. Conversely, if it is 4.0 or more,
Although the metal peelability, heat resistance If:, surface properties, and surface physical properties are improved, the bending resistance, especially the low temperature bendability, is significantly poor. In addition, in the polyurethane constituting the present invention, as the diisocyanate compound and the chain extender compound, compounds other than alicyclic compounds may be used in small amounts.

The polyurethane constituting the polyurethane composition of the present invention is synthesized from the above-mentioned polymeric diol, alicyclic organic diisocyanate, and alicyclic organic diamine, and the method for synthesizing such a polyurethane is as follows: Various methods conventionally conventionally used in the synthesis of polyurethanes can be employed. Next, try impregnating yourself using the representative method.

First, a polymer diol and alicyclic organic diisonane-1 were mixed in a nitrogen atmosphere for 50 to 50 minutes in such a proportion that the incyanate group was in excess of the terminal hydroxyl group of the polymer diol.
The reaction is carried out by heating to 130° C. to obtain polyurecunfre polymer having incyanate groups at the terminals. The obtained jL and this prepolymer were dissolved in a solvent, and the prepolymer was converted into alicyclic chain fψ by an alicyclic organic diamine at a temperature around room temperature.
A long-C polyurethane solution is obtained.

Next, the solvent, which is a component constituting the polyurethane composition of the present invention, must contain tetrahydrofuran as an essential component, the amount of which is 40 to 85% of the total amount of the solvent.
It is preferably 50 to 70% by weight. It is safe that the remaining 60 to 15% by weight is a compound whose main component is an alcoholic compound. Examples of the alcoholic compound include ingubanol, ethanol, methanol, ethercellosolve, methylcellosolve, etc. Among them, the combination of ingubanol and methanol is particularly preferred from the viewpoint of solution stability. When the amount of tetrahydrofuran is less than 40 hours, K V, f
However, if the enamel feel is insufficient, and if the content exceeds 85%, it will be difficult to ensure the stability of the polyurethane composition.

In addition, by using the remaining 60 to 15i short sword as a compound containing an alcoholic compound as a main component, stability of the m liquid can be obtained. Note that the term "compound containing an alcohol compound as a main component" means two cases: a case consisting only of an alcohol compound, and a case using a mixture of an alcohol compound and another compound. Other compounds used when alcohol-based compounds and other compounds are mixed are:

Examples include toluene, cyclohexanone, methyl ether ketone, and ethyl acetate. The solvent constituting the composition of the present invention may be the one used when synthesizing the polyurethane, or the solvent added to the polyurethane after the reaction.

As mentioned above, from the polyurethane composition of the present invention,
An enamel layer with excellent transparency and surface gloss, excellent metal releasability, excellent bending resistance, light resistance, and resistance to NOx gas formation can be obtained, and furthermore, the polyurethane composition itself has excellent solution stability. Therefore, it is extremely excellent as a resin solution for enamel.

The present invention will be specifically explained below with reference to Examples.

The enamel feel of the enamel-like artificial leather obtained using the polyurethane composition of the present invention in Example 1 was evaluated by visually judging the gloss and transparency.

In addition, bending resistance tg (20℃) and low temperature flexibility (-20℃
) is the stroke width (3 tm at longest, 1 c at shortest)
yn) using a h-bending tester with a bending frequency of 8,600 times/hour, and the test was made based on the number of times until a slight scratch appeared. In addition, the light resistance yellowing is 63 on the fade meter.
Yellowing was observed when exposed to carbon light for 200 hours in a ℃ temperature environment. In addition, NOx gas resistance f′
1 NOx gas 150 I) Discoloration and fading when exposed for 48 hours to a concentration of 150 I) Pm can be seen. The surface physical properties were subjected to a tapered abrasion test for loading 1'w + / 2000 times of rubbing 1. Furthermore, using a fold abrasion tester (Custom type), the loading 21b was subjected to 3000 times of rubbing. The degree of surface wear was inspected and the result was 7. If there are no scratches, mark it with ○, if there is some damage, mark it with △, and if there is damage to the extent that the base is visible, mark it with ×. The heat and pressure resistance is to judge whether the shoe can withstand the temperature and pressure conditions applied to the shoemaker. This is the result of observing the enamel feel. If the luster was lost and the enamel feel was significantly impaired (i'Lfc), it was evaluated as ×, if the enamel feel was slightly impaired, it was evaluated as “o”, and if the enamel feel was not impaired at all, it was evaluated as “O”.

All the raw materials for the polyurethane used in the further pressure examples are indicated using abbreviations, and the relationship between the abbreviations and the compounds is as follows.

Examples 1-6. Comparative Examples 1 to 8 Each volatile polyurethane entomer was produced from the polymeric diol, organic diisocyanate, and chain extender shown in Table 1. That is, the polymeric diol and organic diyne/anate were mixed under nitrogen at 60 to 120°C. After reacting with stirring for 5 to 1.0 hours, the obtained polyurethane prepolymer was dissolved in detrahydrofuran, and then a chain extender of a given elbow was dissolved in ingropanol and methanol.
The mixture was added to the polyurethane prepolymer under a nitrogen atmosphere at 30oC and reacted with stirring for 2 to 5 hours to obtain a 20-fold solution of polyurethane having a predetermined viscosity (2000 centivoids). Also, the solvent composition at this time is tetodihydrofuran: ingropanol: methanol-6
The ratio is 5:21:14 (ffi wiping ratio).

Next, the obtained polyurethane solution was applied onto the metal belt so that the solid content film thickness was 25 microns on average, and on top of that, a porous layer of polyurethane was formed on the surface of the polyurethane-impregnated nylon entangled nonwoven fabric. and then put artificial leather on which a non-porous polyurethane layer is formed.
In this state, the solvent of the solution was completely evaporated at a drying temperature of 45 to 100°C, and then peeled off from the metal belt.
enamel-like artificial leather was obtained. The obtained enamel-like artificial leather was subjected to various tests. The results are shown in Table 2.
.

2. Comparative Example 1 is a case where the prerequisite (1) defined in the present invention and alicyclic diamine are not used, Comparative Example 2゜5.6 is a case where requirement (1) is not used, and Comparative Example 3 is a case where requirement (I),
When neither alicyclic diisocyanate nor alicyclic diamine is used, Comparative Example 4 is a case where forgery (1) and alicyclic diincyanate are not used, and Comparative Example 7.8 is a case where the required song) is not used.

Comparative Example 9 The solvent for the polyurethane used in Example 1 was replaced with a mixed solution of inglobanol and toluene (mixing ratio 1:1), and the polyurethane solution was prepared using this solvent in the same manner as in the previous example. When used as an enamel layer of artificial leather, it was clearly inferior in epmel feel.

Patent applicant: Rishi Co., Ltd. Representative Patent Attorney Ken Honda

Claims (1)

[Scope of Claims] Synthesized from a polymeric diol having an average molecular weight of 1,500 to 3,000, an alicyclic organic diisocyanate, and an alicyclic organic diamine, and under the following conditions (1). (II) and book (I) The polymeric diol is (A) nibrene gelicol polyester diol and/-! i or polytetramethylene glycol, and (B) a mixed diol of 1,5-hexanediol polycarbonate dimer, and the mixing ratio of (A)/(13) is l/1 by weight.
-9/l, (n) at least one of the alicyclic organic diisocyanate and the alicyclic organic diamine. (Ill) The molar ratio of the alicyclic organic diisocyanate to the polymer diaryl is 2.5 to 4.0. and a solvent for dissolving this polyurethane, characterized in that 40 to 85% by weight of the polyurethane is tetrahydrofuran, and 60 to 15M of the solvent is a compound whose main component is an alcoholic compound. Suitable for artificial leather/hypolyurethane composition.