JPH03146515A - Ultrasoft elastomer composition - Google Patents

Abstract

PURPOSE:To provide the subject homogeneous composition not causing the lowering of the compatibility among each component and having excellent mechanical characteristics, especially a displacement-following property by comprising a specific mixture of polyols, a polyisocyanate compound and a diluent. CONSTITUTION:The objective composition comprises (A) a polyol mixture of (i) a poly butadiene polyol and (ii) lactone polyesterpolyol in a weight ratio of 60/40-10/90, (B) a polyisocyanate compound (preferably tolylene diisocyanate) and (C) a diluent (preferably dioctyl phthalate) in an amount of 30-300 pts.wt. per 100 pts.wt. of the sum of the components A and B. The component (i) is preferably a liquid butadienic polymer having OH groups at the molecular ends, a number-average molecular weight of 800-3000 and unsaturated bonds >=70% of which are 1,4-structures. The component (ii) is preferably a polyol having a number-average molecular weight of 400-1500 and prepared by the ring-opening polymerization of a lactone with a diol as an initiator.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to ultra-soft elastomer compositions. Specifically, the polyol component is a mixed polyol that is a blend of a polybutadiene polyol and a lactone polyester polyol, and it relates to an ultra-soft elastomer composition whose mechanical properties, especially displacement followability, are significantly improved by incorporating a diluent. be.

[Problems to be solved by conventional technology and invention]

It has been well known that an ultra-soft MNfJ composition can be obtained by incorporating a large amount of a diluent into a polyurethane elastomer composition.

However, such ultra-soft compositions have not been released as commercial products because they significantly impair the mechanical properties, particularly the displacement followability, which are characteristic of general polyurethane elastomers, making them unusable.

In addition, blending a large amount of diluent into the polyurethane elastomer composition causes problems with the compatibility of the gold component, tends to cause separation, and makes it difficult to obtain a uniform elastomer composition. The drawback was that it was easy to cause bleed.

[Means for solving problems]

An object of the present invention is to eliminate such drawbacks and provide an ultra-soft elastomer composition that has excellent mechanical properties, particularly excellent displacement followability.

The inventors of the present invention have conducted extensive research based on the above-mentioned objectives, and have found that when producing a polyurethane elastomer by reacting a polyol with a polyisocyanate, a mixed polyol containing a polybutadiene polyol and a lactone polyester polyol as a polyol component is used. It has been found that the compatibility with the diluent and the polyisocyanate compound is improved and the mechanical properties are significantly improved.

The present invention was completed based on this knowledge. That is, the present invention produces a polyurethane elastomer by reacting a polyol and a polyisocyanate, and (b) a mixed polyol obtained by blending a polybutadiene polyol and a lactone polyester polyol in a weight ratio of 60/40 to 10/90. Total amount of polyisocyanate compound (C) (a), (bl) 30 per 00 parts by weight
An ultra-soft elastomer composition comprising ~300 parts by weight of diluent is provided. The present invention will be explained in detail below.

The mixed polyol used in the present invention is composed of a blend of polybutadiene polyol (■) and lactone polyester polyol (■), and the weight ratio (■/■) is 60/4.
It is 0 to 10/90. Weight ratio (■/■) is 60/4
When the amount is more than 0, the mechanical properties, especially tensile strength and tensile elongation rate, are significantly reduced and the displacement followability becomes poor, and when it is less than 10/90, there is a lack of compatibility with the diluent and the polyisocyanate compound, and moisture in the air, Under the influence of water vapor, the composition becomes a composition with a strong surface tackiness or an uncured surface.

Here, polybutadiene polyol has a hydroxyl group in the molecule, preferably at the end of the molecular chain, has a number average molecular weight of 500 to 5,000, and preferably has at least 70% of the unsaturation in the polymer having a 1,4-dioxide structure. is 800-3,000
It is a liquid butadiene polymer, for example, the trade name pol
y bd (manufactured by Idemitsu Petrochemical Co., Ltd.) etc. can be used.

In addition, lactone-based polyester polyol is obtained by ring-opening polymerization of lactone using a diol as an initiator and has a number average molecular weight of 300 to 3,000, preferably 400 to 1.5.
00 polyol.

If the number average molecular weight is 3.000 or more, sufficient reaction will not be obtained and the resulting composition will be difficult to cure, which is not preferred. For example, the product names Plaxel (made by Daicel Chemical Industries, Ltd.) and Crapol (made by Kuraray) can be used.

Further, the polyisocyanate compound is an organic compound having two or more isocyanate groups in one molecule, and has an isocyanate group reactive with the active hydrogen-containing functional group of the mixed polyol. Examples of polyisocyanates include the customary aromatic, aliphatic and cyclic ones, such as tolylene diisocyanate (TDI), hexamethylene diisocyanate, diphenylmethane diisocyanate (MD I),
Liquid modified diphenylmethane diisocyanate (liquid MD
I), polymethylene polyphenylisocyanate, naphthalene-1,5-diisocyanate, xylene diisocyanate, cyclohexyl diisocyanate, especially TD! , MDI, transverse MDI, etc. are pregnant. Alternatively, it is more preferable to use a compound having a terminal isocyanate obtained by reacting the above compound with an active hydrogen-containing compound. These polyisocyanate compounds may be used alone or in combination of 24 or more Ef1.

The blending ratio of the above mixed polyol and polyisocyanate compound is not particularly limited, but usually the molar ratio of the isocyanate group (NGO) of the polyisocyanate compound to the hydroxyl group (OH) of the mixed polyol, that is, NGOlo
H is 0.6-2.0, preferably 0.8-L5, more preferably 09-1.15. If this molar ratio is outside the above range, the resulting composition will be difficult to cure, and even if cured, the composition will have poor mechanical properties, which is not preferred.

In the present invention, the diluent is used as one component of the composition in a total amount of 10
30-300, preferably 50-200 per part by weight
It is necessary to use parts by weight. If it is less than 30 parts by weight, phase separation of each component will occur during the storage of the 4-polyol and during the reaction for producing the elastomer, and if it is more than 300 parts by weight, the diluent incorporated in the composition will deteriorate over time. This is not preferable because it tends to cause bleeding due to metastasis.

Here, the diluent refers to diluents for ordinary polyurethane resins, such as phthalate ester, fatty acid ester, phosphate ester, polyester, and epoxy diluents, especially dioctyl phthalate. (DOP), dibutyl phthalate (DBP), and the like are preferred. These diluents may be used alone or in combination of two or more.

In the present invention, the mechanical properties of the composition, particularly the bow tensile strength,
Various organic and inorganic fillers can be used as desired to increase tensile elongation.

Among these, examples of inorganic substances include calcium carbonate,
Talc, clay, mica, graphite, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, calcium sulfate, zinc oxide, aluminum oxide, titanium oxide, iron oxide, silicic anhydride, glass flakes, carbon blank, silica, rock wool, etc. be. These shapes are powdery, scaly, and fibrous, and can be used as is, but the physical properties of the elastomer composition can be improved by subjecting the surface to titanium treatment, silicone treatment, etc. in advance.

Organic materials include debris, pine resin, resin powder, wood flour, animal and plant fibers, and artificial fibers.

In addition to the above, minute hollow spheres can also be used.

In carrying out the present invention, known urethanization catalysts such as tertiary amine compounds and organometallic compounds are used as necessary, such as triethylenediamine, 1,4-hexamethylenediamine, 1,4-butanediamine, etc. , lead octylate, dibutyltin laurate, and the like.

In addition, in the present invention, in order to increase the durability of the composition,
As the stabilizer, one or more of Peng stabilizers, antioxidants, ultraviolet absorbers, and ultraviolet stabilizers can be used as necessary.

As the heat stabilizer, tetramethyl-thiuram disulfide, copper dimethyl-dithiocarbamate, etc. are used.

Positionally hindered phenols are used as antioxidants,
For example, the product names Irganox 1010.1076 (manufactured by Ciba Geigy) and Yoshinox BHTSBB (
Examples include products manufactured by Yoshitomi Pharmaceutical Co., Ltd.).

As an ultraviolet absorber, for example, the product name Tinuvin P, 32
7.328 (benzotriazoles such as Ciba-Geigy (manufactured by M), or brand name Tomisorb 800 (Yoshitomi Pharmaceutical ■)
Benzophenones such as those manufactured by J.D. Co., Ltd. may be used.

In addition, as an ultraviolet stabilizer, for example, the product name Sanol LS
770.774, Tinuvin 144 (manufactured by Ciba Geigy ■)
Preferably, positionally harmful amines such as

In addition to the various additives mentioned above, pigments, dyes, flame retardants, antifoaming agents, dispersants, surface modifiers, etc. can also be added as necessary.

In the ultra-soft elastomer set 5I2ryJ of the present invention, the mixed polyol, polyisocyanate compound, and diluent may be stored separately until just before use, or the diluent may be mixed with the preol mixture, and mixed at the time of use.

If other substances are to be added, they may be added at the time of use, or may be mixed with the polyol mixing wave.

Mix each component thoroughly and pour into a mold at room temperature to 70°C.
The reaction is carried out at room temperature to 90°C for 30 to 180 minutes, and the cured ultra-soft elastomer composition is taken out from the mold.

[Action and effect]

The obtained elastomer composition had a uniform appearance, showed no surface tackiness due to phase separation of each component, and had a hardness (J
IS Z2246) A-0 to A-15, hardness (Durometer hardness test, Asker C type hardness tester) C-0 to C-
30 extremely flexible ultra-soft elastomer composition.

In addition, mechanical property test values are determined by tensile test (JIS K83
01 Type B dumbbell test piece) tensile strength 0.5-12
kg/aI, maximum tensile elongation rate of 500% or more, and exhibits extremely excellent displacement followability.

Conventional polyurethane elastomers on the market have a hardness of CJTS Z2246) A-10 or higher,
One of the reasons why ultra-soft elastomers with a hardness of A-10 or less did not reach the market was that they had poor displacement followability (tensile elongation rate of 5
00% not m>r? ! It is presumed that it could not withstand any use.

The elastomer composition according to the present invention changes with little stress due to its unique ultra-softness, has excellent displacement followability, and generates extremely little stress even when subjected to displacement, so it can be used as a vibration damping material, a shock absorbing material, a sealing material, etc. gasket, packing,
It can be used as a soft adhesive, etc. However, the circumferential speed is not limited to these.

[Example] The great invention will be explained in more detail with reference to Examples below.

Examples 1 to 6 and Comparative Examples 1 to 4 The ingredients shown in Tables 1 to 2 (units are parts by weight) other than the isocyanate component were mixed, then the isocyanate components were mixed, and this was mixed into a 200 mm x 200 mm x 3 mm thick silicone open tube. It was poured into a mold. After leaving it at 60°C for 2 hours, mold it and then leave it at room temperature at 7F! After curing for a while, a polyurethane elastomer composition was obtained.

Performance was evaluated using the following method. The results are shown in Examples 1-
2 and Comparative Examples 1 to 3 are shown in Table 1, and Examples 3 to 3 are shown in Table 1.
6 and Comparative Example 5 are shown in Table 2, respectively.

The performance evaluation method is as follows.

○ Stability of mixed components The stability over time of a mixed solution of mixed polyol and diluent is judged by the presence or absence of separation of each component. If there is no separation, it is marked as (good), and when there is separation, it is marked as (poor). .

○Surface condition of the composition The compatibility of the mixed polyol with the diluent and isocyanate components after mixing was determined by determining whether the surface condition of the demolded elastomer composition was the same or different on the oven surface and the bottom surface,
When they are the same, they are written as (good), and when they are different, they are written as (bad).

○Hardness durometer - Hardness test method, measured using an Asker 〇 type hardness needle.

○Mechanical property test of composition The tensile strength and tensile elongation rate are measured using a B-type dumbbell test piece according to JIS K6301.

○Ingredients polyol l: poly bd R-15H T (manufactured by Idemitsu Petrochemical Corporation) 2: Plaxel 208 (manufactured by Daishichiru Chemical Industry Corporation) TMHDA: Tetramethylhexanediamine DBTL dibutyltin dilaurylate isocyanate A: MDI and polyol ( Number of 2 functional groups, molecule ff1
2,000) with a terminal isocyanate content of 9.91%.

Isocyanate B: A compound with a terminal isocyanate content of 2.25% obtained by reacting TDI with a polyol (two functional groups, molecular weight 2,000).

boliol

Claims (3)

[Claims] (1) When producing a polyurethane elastomer by reacting a polyol and a polyisocyanate, (a) a mixed polyol obtained by blending a polybutadiene polyol and a lactone polyester polyol at a weight ratio of 60/40 to 10/90 (b) a polyisocyanate compound (c) 30 per 100 parts by weight of the total amount of (a) and (b)
Ultra-soft elastomeric composition comprising ~300 parts by weight of diluent. (2) The ultra-soft elastomer composition according to claim 1, wherein the polybutadiene polyol has a 1,4 structure in which at least 70% of the unsaturation in the polymer is present. (3) The lactone-based polyester polyol has a number average molecular weight of 300 to 3,000 obtained by ring-opening polymerization of lactone using a polyol as an initiator.
The ultra-soft elastomer composition described in .