JPS62135513A - Elastomer-forming composition - Google Patents

Abstract

PURPOSE:To obtain a composition which can form a polyurethane elastomer low in a change in hardness at low temperature, by mixing a specified polyol component with a specified polyisocyanate component. CONSTITUTION:A composition comprising a polyol component (A) comprising a polyol (A1) which is an oxyethylene ether and/or oxypropylene ether of a polyalcohol and/or an amine and has an equivalent of 100-3,000 and a polyol (A2) which is a copolymer of tetrahydrofuran with ethylene oxide and/or propylene oxide and has an equivalent of 400-2,000, an organic polyisocyanate component (B) and, optionally, a catalyst (C). The average functionality of polyol (A2) used is usually 2.1 or above, and the weight ratio of polyol (A1) to polyol (A2) is usually 95:5-5:95.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to elastomer-forming compositions.

[Conventional technology]

Conventionally, polyurethane elastomers made of polymers of tetrahydrofuran and alkylene oxide, organic polyisocyanates, and low-molecular linear aliphatic diols are known (Japanese Patent Publications No. 57-48012 and qβ58-7648). .

[The interlayer point that the invention attempts to solve]

However, such elastomers have the disadvantage that their hardness changes significantly at low temperatures, making them unsuitable for use in winter or in cold regions.

[Means to solve the problem]

The present inventors have arrived at the present invention as a result of research aimed at obtaining a composition that forms an elastomer with a small change in hardness at low temperatures.

That is, the present invention provides oxyethylene ether and/or oxypropylene ether of polyhydric alcohols and/or amines with an equivalent weight of 100 to 3.000.
A polyol component hole consisting of a polyol (A1) and a polyol component (A2) which is a copolymer of tetrahydrofuran and ethylene oxide and/or propylene oxide and has an equivalent weight of 400 to 2,000;
This is a polyurethane elastomer-forming composition characterized by comprising an organic polyisocyanate component (B); and, if necessary, a catalyst (C).

In the present invention, polyhydric alcohols of polyol (A1) include dihydric alcohols (ethylene glycol, propylene glycol, 1.4-butanediol, 1.3-
butanediol, N-methyljetanolamine, etc.)
; Trihydric alcohol (glycerin.

trimethylolpropane, triethanolamine, etc.)
; Examples include tetrahydric or higher alcohols (pentaerythritol, sucrose, etc.).

Amines include aliphatic amines (ethylamine).

(ethylenediamine, etc.); aromatic amines (tolylene diamine, methylene dianiline, polymethylene polyphenylamine, etc.); and heterocyclic amines (N-aminoethylpiperazine, etc.). Polyhydric alcohols and amines can be used as a mixture of two or more. Among these, preferred are polyhydric alcohols having 3 active hydrogen atoms or amines, and particularly preferred are glycerin or N-aminoethylpiperazine.

The equivalent of (80) is usually 100 to 3000, preferably 25
It is 0 to 2.000. Polyols having an equivalent weight of less than 100 cannot improve low-temperature properties. Also, the equivalent is s
, o o o, the strength of the obtained elastomer is so low that it is not practical.

The average number of functional groups in (A,) is usually 2.1 or more, preferably 2.1 to 50, particularly preferably 2.3 to 3.5.

If the average number of functional groups is less than 2.1, an elastomer with poor low-temperature properties cannot be obtained, and if it exceeds 5.0, the resulting elastomer becomes brittle.

Oxyethylene ether and/or oxypropylene ether of polyhydric alcohols and/or amines can be added to polyhydric alcohols and/or amines with ethylene oxide (hereinafter abbreviated as EO) and/or propylene oxide (hereinafter referred to as P).

) can be obtained by adding the compound under pressure in the presence of a conventional alkali catalyst (KOH, N, LOH, etc.).

As the polyol (A2) in the present invention, a block copolymer and a random copolymer of tetrahydrofuran (hereinafter abbreviated as THF) and EO and/or PO can be used. The content of EO and/or PO in (A2) is usually 5 to 90%, preferably 10 to 50% by weight. If the content of EO and/or PO is less than 5%, an elastomer with the desired low temperature properties cannot be obtained;
If it exceeds this, the water resistance of the obtained elastomer will deteriorate.

The equivalent of (A2) is usually 400 to 2,000, preferably
800 to 2,000. If the equivalent weight is less than 400, the obtained elastomer will have poor low temperature properties;
When it exceeds 0, the strength of the obtained elastomer decreases beyond the practical range.

(A2) can be produced by various methods. Block copolymers can be produced by, for example, adding EO and/or PO to polytetramethylene ether glycol, or adding THF to polyoxyethylene glycol, polyoxypropylene glycol, or polyoxyethylene oxypropylene glycol. can get. The method of adding EO and/or PO may be a method of adding under pressure in the presence of a conventional alkali catalyst (KOH, NdOH, etc.). Further, the THF addition may be carried out in the presence of a catalyst (such as a Lewis acid). Random copolymers may also include, for example, THF and EO and/or P.
O as initiator (water, ethylene glycol.

1,4-butanediol, etc.) and catalysts (Lewis acids, etc.)
It is obtained by reacting in the presence of.

The castor oil polyol and/or liquid polydiene polyol described above can be used in combination.

In this case, the amount of (A2) is usually 10% or more, preferably 50% or more, based on the total ff1ffi of (A2) and castor oil-based polyol and/or liquid polydiene-based polyol.
It is greater than or equal to θ.

The organic polyisocyanate component (B) in the present invention includes aromatic polyisocyanates (2,4-tolylene diisocyanate, 2.6-) lylene diisocyanate), 2.4-) lylene diisocyanate and 2.
6-1-lylene diisocyanate mixture, xylylene diisocyanate, 1,5-naphthylene diisocyanate, diphenylmethane-4,47-diisocyanate,
Modified (carposiimide-modified, etc.) polyisocyanates based on diphenylmethane-464'-diisocyanate, which are liquid at room temperature.

m- and p-phenylene diisocyanate, triphenylmethane triisocyanate, 1. ．． 3-bis(phenylmethyl)benzene-4,4',4"-triisocyanate, etc.); Aliphatic diisocyanates (hexamethylene diisocyanate, etc.); Alicyclic M diisocyanates (isophorone diisocyanate, cyclohexane-1)
, 4-diisocyanate, 1,4-methylenebis(cyclohexyl isocyanate), etc.) and mixtures of two or more thereof can be used.

Among these organic polyisocyanates, aromatic polyisocyanates are preferred, and 2 are particularly preferred.
．． 4-Tolylene diisocyanate ta is a mixture of 2.4-)lylene diisocyanate and 2.6-tolylene diisocyanate.

The catalyst (C) used as necessary in the present invention is a metal catalyst (dibutyltin dilaurate).

Dibutyltin malate, stanas octoate.

bismuth chloride, lead octylate, ferritic acetylacetonate, etc.); amine catalysts (triethylamine, triethylenediamine, N,N'-dimethylpiperazine, N-ethylmorpholine, etc.), and combination systems of two or more of these. .

Among these, metal catalysts are preferred, and dibutyltin dilaurate is particularly preferred.

In the present invention, additives may be used in addition to the above-mentioned components depending on the case. Additives include reinforcing agents (carbon black, white carbon, colloidal silica, etc.); inorganic fillers (calcium carbonate).

Barium sulfate, talc, clay, silica powder, etc.); Plasticizers (dibutyl phthalate, dioctyl phthalate, chlorinated normal paraffin, etc.); Diluents (petroleum resins, xylene resins, etc.); Solvents (toluene, xylene, methyl nityl ketone, acetic acid) ethyl, etc.); antioxidants, flame retardants, and colorants.

In the composition of the present invention, the weight ratio of polyol (A1) to polyol (A2) is usually 95:5 to 5:95, preferably 85:15 to 15:85. (A1) is 9
When it is more than 5, an elastomer with excellent low-temperature properties cannot be obtained, and when it is less than 5, the strength of the obtained elastomer becomes low.

Polyol component (5) and organic polyisocyanate component (
The equivalent ratio of B) is usually 2:1 to 1:2. Preferably 1%1
:1 to 1:1.5.

The amount of catalyst (C) used is usually 5% or more, preferably 0.001 to 0.01%, based on the total weight of (5), (B), and (C).
It is 1%.

A formulation example of the composition of the present invention is as follows.

Percentages are by weight.

(A,): Usually 5-85%, preferably 10-60%
(A2) Usually 5 to 85%, preferably 10 to 60% (
B) Usually 3 to 30%, preferably 5 to 20% (C) Usually θ to 5%, preferably 0.001 to 1% In the composition of the present invention, the polyol component and the organic polyol component (B) There are no particular restrictions on how it can be used, including a method in which each component is used simultaneously (the so-called one-shot method), a method in which a polyol, a portion of the components, and an excess organic polyisocyanate are reacted in advance to synthesize a prepolymer of terminal isocyanate. The prepolymer and the remainder of the polyol component (B) are reacted at 80 to 110° C. for 5 to 10 hours to synthesize a terminal isocyanate prepolymer (B').

Then, the remaining components (A') and (
B') at 60-125°C, preferably '10-J 10
Heat to 0℃.

(A') component, rB acid component, catalyst (C) (
After thoroughly stirring and mixing a predetermined amount of additives (A') or (may be mixed in 800 g) in advance and, if necessary, degassing the whole, preferably 70
Pour into a mold heated to ~130°C.

In some cases, a cylindrical mold may be used, and the mixture may be rotated around a central axis until it gels, and the centrifugal force applied to the mixture may be used in a so-called centrifugal molding method, or spraying may be performed. good.

Alternatively, the two liquids (A') and CB') can be measured and mixed by stirring using a machine. The machines that can be used for the composition of the present invention are not particularly limited. There is no particular problem as long as it is equipped with a mixer that stirs and mixes the liquid and discharges the mixture.

The cast product is cured at 70 to 130'C for about 5 minutes to 2 hours, and then removed from the mold. The demolded elastomer cast product is aged at room temperature or by heating until it develops its final strength. Preferred aging is 70-130'O
This is done by heating for 10 minutes to 24 hours and then leaving it at room temperature for one week or more.

〔Example〕

The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto. The parts described below indicate parts by weight.

Example 1 Composition of the present invention AI (1): 84.9 parts A2 (1): too parts B (1): 10.4 parts C (1): 0.05 parts (Note 1) AI (1) : Glycerin po adduct (equivalent weight 1700)
A2 (1): THF and EO silane copolymer diol (EO content 25%, equivalent weight 1500) B (1): 2.4-) lylene diisocyanate equivalent ratio: 1.08 A, (1) ten A2 (1) A2 in a 4-hole flask equipped with a stirring bar and thermometer.
(1) Pour 100 parts and reduce to 110 parts under reduced pressure of 3 Dragon Hf.
It was heated to °C and dehydrated for 1 hour. Next, set B(1) to l
014 parts were added and reacted at 100° C. for 8 hours under a nitrogen stream to obtain prepolymer B' (1). The free isocyanate content of B'(1) was 2.0%.

110.4 parts of B' (1) and 84.9 parts of A,
Weigh each of (1) in a beaker at 80°C, add 0.05 part of C(1) to the beaker, mix thoroughly for 30 seconds with a baby motor with a screw type stirring blade, and
After degassing for 1 minute at a reduced pressure of mHy, the temperature was immediately <100°C.
It was poured into a preheated mold. After heating the mold at 100° C. for 1 hour, the cured product was demolded to obtain a sheet-like urethane resin molded product with a thickness of 2 I++m. 10 pieces of the obtained molded product
After heat curing at 0°C for 15 hours, leave it at room temperature for 1 week.
After that, it was subjected to physical property measurements.

Example 2 Composition of the present invention A, (2): 99.9 parts A2 (2): 100 parts B (1): 10.4 parts C (1): 0.05 part (Note 2) A, ( 21: N-aminoethylpiperazine PO-EO
Adduct (EO content: 15%, equivalent weight: 2000) PO
, EO added in the order of A2 (2), a copolymer of two THE and po (PO content 30%, equivalent weight 1500) Example 1 using 100 parts of A2 (21 and 10.4 parts of B (1)) Prepolymer B″(1) was obtained in the same manner as above.The free isocyanate content of B″(1) was 2.0%.
Met.

110.4 parts of 8' (1), 99.9 parts of A, (2
) and 005 parts of C(1) were used in the same manner as in Example 1 to obtain a molded article for physical property measurement.

Comparative Example 1 Comparative composition CA+(t) + 2.2 parts A2(1): 100 parts B (1): 10.4 parts (Note 3) CA1(1): 1.4-Butadiol B (1)
.

Equivalence ratio CA1(1) wa°1°03 In fact, prepolymer B'(1) obtained in Example 1 wo110.
Example 1 using 4 parts and 2.2 parts OCA, (D)
A molded product for physical property measurement was obtained in the same manner as above.

Trial 4. Column 1 Performance test of the compositions of Examples 1 and 2 and ratio example 1;
'I was frugal. The results are shown in Table-1.

Table 1 Note) Measurement method JIS K 6801 [Effects of the invention] The composition of the present invention forms an elastomer with excellent low-temperature durability. That is, the elastomer obtained from the composition of the present invention shows little change in hardness at low temperatures and can be used over a wide temperature range.

Conventional elastomers, such as the compositions described in Japanese Patent Publication No. 57-48012 and Japanese Patent Publication No. 58-76j8, have a large change in hardness at low temperatures;
Although it has been limited to use in winter or in cold regions, these limitations can be greatly alleviated by application of the composition of the present invention.

Furthermore, the elastomer obtained from the composition of the present invention has low hardness and a large coefficient of friction against electricity and metals.

Furthermore, the pot life and curing rate can be arbitrarily adjusted to a certain extent by adjusting the amount of catalyst, and the shape and size of the molded product can be selected from a wide range.

If a polyester polyol is used instead of polyol (A,) in the composition of the present invention, an elastomer having such an effect cannot be obtained.

Since it has the above-mentioned effects, the elastomer-forming composition of the present invention is suitable for paper feed rolls of copiers and the like, which often have problems when starting up in winter. The method of forming the paper feed roll can be arbitrarily selected depending on the mechanism of the machine in which it is used. For example, in the case of large rolls, it is possible to use a method in which the elastomer is integrally coated with a metal core that has been treated to improve adhesion using a mold, etc., and in the case of small rolls, the elastomer is coated with a donut-shaped elastomer in advance. It is possible to use a method such as processing the elastomer into a sloping shape using a mold, etc., and fitting the elastomer into a metal core.

The elastomer-forming composition of the present invention can be widely applied to printing rolls, vibration damping materials, industrial parts, etc. in addition to the above-mentioned uses by taking advantage of its excellent effects.

Claims (1)

[Scope of Claims] 1. Polyol (A_1) which is oxyethylene ether and/or oxypropylene ether of polyhydric alcohol and/or amines and has an equivalent weight of 100 to 3,000, and tetrahydrofuran and ethylene oxide and/or or a polyol component (A) consisting of a polyol (A_2) which is a copolymer with propylene oxide and has an equivalent weight of 400 to 2,000; an organic polyisocyanate component (B); and, if necessary, a catalyst (C
) A polyurethane elastomer-forming composition comprising: 2. The composition according to claim 1, wherein the average number of functional groups in (A_1) is 2.1 or more. 3. The weight ratio of (A_1) and (A_2) is 95:5 to 5:
95. The composition according to claim 1 or 2, wherein the composition has a molecular weight of 95.