JPS6126616A - Preparation of polyurethane having improved performance - Google Patents

Abstract

PURPOSE:To obtain the titled polymer useful as casting elastomer, adhesive, waterproof material, floor covering, etc., having improved resistance to hydrolysis, mildew resistance, low-temperature characteristics, oil resistance, wear resistance, adhesiveness, etc., by reacting a specific polyol with an isocyanate. CONSTITUTION:(A) A polyol having a group shown by the formula I and a group shown by the formula II in the molecule in a weight ratio of 1/4-4/1 and 600-7,000 average molecular weight, obtained by subjecting beta-methyl-delta-valerolactone to polymerization through ring opening with polytetramethylene ether glycol is reacted with (B) an organic polyisocyanate (e.g., diphenylmethane diisocyanate, etc.), and if necessary, (C) a chain extender (e.g., butanediol, etc.), to give the aimed polymer.

Description

[Detailed description of the invention] The present invention has hydrolysis resistance, mold resistance, low temperature properties, oil resistance,
This invention relates to a method for producing polyurethane with excellent abrasion resistance, adhesive properties, etc.

Conventionally, polyether polyols and polyester polyols have been commonly used in the production of polyurethane, but polyester polyols are superior in terms of abrasion resistance, strength and elongation, oil resistance, solvent resistance, adhesiveness, etc. However, polyether polyols are better in terms of hydrolysis resistance and mold resistance, and both polyether polyols and polyester polyols have advantages and disadvantages. In order to overcome both of these drawbacks, copolymerization of polyether polyols (e.g. polytetramethylene glycol) and polyester polyols (e.g. polycaprolactone glycol) and the use of polytetramethylene glycol modified with ε-caprolactone at both ends were devised. However, the reality is that the shortcomings of both are more obvious and there is little sense of improvement.

In view of these circumstances, the present inventors have conducted various studies on a method for producing polyurethane that combines the advantages of polyether polyol and polyester polyol and also has excellent low-temperature properties. A polyol having an average molecular weight of 600 to 7000, which has an extender as a base and a -(C1t(2)ao- group (B), and has a weight ratio of (A)/(B) of 1/4 to 4/1. What is a polyol with an average molecular weight of 600 to 7000 that has the characteristics of a polyester polyol without reducing hydrolysis resistance and mold resistance and has excellent low temperature properties and has (CH2) 40- groups? Specifically, the ratio (A)/(B) of β-methyl-δ-valerolactone to polytetramethylene ether glycol (CH2)40- group (B) is 1/4 to 4/ 1 is a good range for achieving the effects of the present invention.More preferably, it is 1/3 to 3/1.The polymer polyol obtained in this way has no crystallinity or has only a small amount of crystallinity. Therefore, even when made into polyurethane, crystal hardening of the soft segment is not observed, and it has excellent low-temperature properties.As the weight proportion of A groups increases, the crystallinity decreases and liquefaction occurs. Therefore, when a liquid state is strictly required, it is preferable to increase the weight proportion of the A group.

As described above, the polyol of the present invention has a lower viscosity than polytetramethylene glycol, and has excellent workability when used for foams, microcellular, adhesives, cast-molded distomers, waterproofing materials, flooring materials, etc. In addition, it has extremely good hydrolysis resistance, mold resistance, low temperature properties, tensile strength, abrasion resistance, oil resistance, and adhesion, combining the advantages of polyether and polyester polyurethanes. .

In addition, in the present invention, polytetramethylene glycerol: 2-#
β-methyl-δ-valerolactone [when polymerized,
Furthermore, other lactones, such as ε-caprolactone, can be ring-opened and copolymerized. However, if too large a quantity of other lactones is introduced, it will lead to a decrease in hydrolysis resistance.
It is preferable to keep it below 0.

The molecular weight of the polyol used in the present invention is in the range of 600 to 7,000. If it is less than 600, the low temperature properties and flexibility will be poor, and if it is more than 7,000, it will be unfavorable in terms of strength and physical properties.

It is believed that the reason why the low temperature properties are good in the present invention is that the polytetramethylene oxide group is located almost in the center of the polymer polyol molecule.

Also, based on a concept similar to the present invention, polytetramethylene y f
Polymer glycol obtained by ring-opening polymerization of ε-caprolactone using IJ call has extremely low hydrolysis resistance and mold resistance, and is therefore not a desirable modification, and it is completely impossible to predict the effects of the present invention from this fact. It is.

As described above, the polyurethane using the polymer polyol of the present invention is an epoch-making polyurethane having performance that cannot be obtained by conventional techniques.

The organic polyisocyanate used in the present invention includes:
For example diphenylmethane diisocyanate, 2.4-
) lylene diisocyanate, 2.6-) lylene diisocyanate, phenylene diisocyanate, 1.5-naphthylene diisocyanate, 3゜3'-dichloro-4,
Aromatic diisocyanates such as 4'-diphenylmethane diisocyanate, xylylene diisocyanate, and toluylene diisocyanate, and aliphatic or fatty acids such as hexamethylene diisocyanate, inphorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and hydrogenated xylylene diisocyanate. Examples include cyclic diisocyanates. Polyisocyanates may be used alone or in combination.

Furthermore, in the synthesis of polyurethane, low-molecular compounds having two or more active hydrogen atoms are usually used as chain extenders, and these active hydrogen atom compounds can also be used in the method of the present invention. Representative examples of these active hydrogen atom-containing compounds include ethylene glycol, butanediol, propylene glycol, 1.6
-hexanediol, 1,4-bis(β-hydroxyethoxy)benzene, 1,4-cyclohexanediol,
Diols such as bis(β-hydroxyethyl) terephthalate and xylene glycol, water, hydrazine, ethylene diamine, propylene diamine, xylylene diamine, isophorone diamine, piperazine, phenylene diamine, tolylene diamine, adipic acid dihydrazide, isophthalic acid dihydrazide, etc. These compounds may be used alone or in combination. Furthermore, if necessary, a -valent low-molecular alcohol, low-molecular amine, or the like may be used as a modifying agent.

As for the operation method for obtaining polyurethane, known urethanization reaction techniques are used. For example, a polyol and a low-molecular compound having active hydrogen are mixed, and the ratio of the number of active hydrogen atoms to the NCO group of these compounds is about 1:0.7 to
Polyurethane can be obtained by adding a polyisocyanate compound in a ratio of 1:1.3 and reacting at a temperature of about 60 to 150°C, but in order to obtain a higher molecular weight, NCO and OH The molar ratio should be made as close to 1 as possible. This reaction can also be carried out in a solvent consisting of one or more of ethyl acetate, dimethylformamide, dimethyl sulfide tetrahydrofuran, impropatol, methyl ethyl ketone, toluene, ethyl cellosolve and the like. The concentration at this time is preferably within the range of 10 to 70% by weight.

The present invention will be specifically explained below using Examples.

In addition, in the examples, hydrolysis resistance refers to the obtained thickness of 200μ
The film was left in an atmosphere with a relative humidity of 95 degrees Celsius and a temperature of 7 degrees Celsius (jungle test conditions) for 10 weeks, and then the surface stickiness, surface cracks, peeling, etc. were examined, and if there were no changes, ◎, and the degree of stickiness is indicated by × or XX for those with large cracks, peeling, or stickiness on the 01 surface. Mold resistance was measured after 4 months of inoculating a mixed spore suspension of 5 types of mold on a glucose peptone agar culture medium with a 200μ thick film and culturing at 30'C with a humidity of 90-95%. The condition of the surface deterioration was investigated, and those with no change are rated ◎, and those with cracks due to mold are rated ×.
Items with large cracks are indicated by XX. In addition, this test included Aspergillus niger ATCC9642, Penicillium luteum ATCC9644, Rhizopus nigricans S, N, 32, and Trichoderma T-I ATCC9 described in JIS Z2911-1960 mold resistance test.
645, Chaetomium globosum ATCCll5205
Five types of molds were used.

Solvent resistance was measured by making a polyurethane film into a 200 μm thick film and expressing it by the degree of weight swelling after immersing this film in toluene for 24 hours. For low-temperature properties, use the direct-reading dynamic viscoelasticity measuring device Bipron Model manufactured by Toyo Saiki.
Main dispersion temperature (T
Evaluation was made by measuring α.

The oxidative deterioration resistance of a 70μ thick film at 120°C is 2.
It was expressed as the tensile strength retention rate after standing for 00 hours.

Furthermore, the polyols, polyisocyanates, and chain extenders used as raw materials for the polyurethanes used in the examples are shown using abbreviations, and the relationship between the abbreviations and compounds is as shown in Table 1.

Example 1, Comparative Example 1.3.4 Polyurethane was produced using the raw materials shown in Table 2.

That is, predetermined amounts of polyol, polyisocyanate, and chain extender were reacted in ethyl acetate at 75°C under nitrogen to obtain a polyurethane having a solid content of 40% by weight.

After adjusting the polyurethane concentration of this solution to well over 10% by weight, this solution was cast onto a glass plate and dried to a thickness of 70 μm.
and a 200μ film was obtained.

This film was subjected to various physical property tests. The results are shown in Table 3.

Example 2.5, Comparative Example 2 Using the raw materials shown in Table 2, the reaction was carried out in the same manner as in Example 1 to obtain polyurethane having terminal hydroxyl groups.

10 parts of Coronate L was added to this polyurethane solution. A film was obtained from this polyurethane solution in the same manner as in Example 1, and was subjected to various physical property tests.

Table 1 Table 2 (*1) Curing agent: Number of parts of Coronate L, which is a curing agent, per 100 parts by weight of polyurethane

Claims (1)

[Claims] When manufacturing polyurethane by reacting a polyol with a polyisocyanate and, if necessary, a chain extender, there are ▲mathematical formulas, chemical formulas, tables, etc. in the molecule as a polyol component▼group (A) and -(CH_2)_4O- group ( B) and the ratio of (A)/(B) is 1/4 to 4/1 by weight
A method for producing polyurethane, characterized by using a polyol having an average molecular weight of 600 to 7,000.