JPS63130616A - Flexible elastomer composition - Google Patents

Abstract

PURPOSE:To make it possible to form a flexible polyurethane elastomer composition remarkably improved in mechanical properties, by mixing a specified polyolefin polyol with a polyisocyanate compound and an inorganic filler. CONSTITUTION:This flexible elastomer composition is formed from a polyolefin polyol (a) obtained by hydrogenating at least 90% of the double bonds of polyhydroxypolybutadiene having at least 70% 1,2-bonds, a polyisocyanate compound (b) and 5-300pts.wt., per 100pts.wt. in total of (a) and (b), inorganic filler. It has a surface hardness (as specified in JIS K-6301) <=90A. In order to control the hardness and to improve the workability, it is preferable to add 10-300pts.wt., per 100pts.wt. in total of (a) and (b), plasticizer to said elastomer composition.

Description

[Detailed description of the invention] [Industrial application field] FIELD OF THE INVENTION The present invention relates to soft elastomer compositions.

More specifically, the present invention relates to a soft polyurethane elastomer composition whose main component is a polyolefin polyol having a specific structure and which has significantly improved mechanical properties by being filled with an inorganic filler.

[Prior art and its problems] Conventionally, polyurethane distoners whose main components are polyhydroxydiene polyols that do not contain polar groups such as esters and ethers in their main chains have high electrical insulation properties and are non-moisture permeable. It is known to have excellent hydrolysis resistance.

However, polyhydroxydiene-based urethane elastomer is a general polyether-based elastomer.

Since it has a lower mechanical strength than polyester-based urethane elastomers, most of its uses have been limited to special molecules that do not require high strength.

It was a long time ago. Polyhydroxydiene polyol.

It is also known that heat resistance and mechanical properties can be significantly improved by hydrogenating the double bonds to form a polyolefin polyol.

However, even in polyurethane containing polyolefin polyol as a main component, sufficient mechanical strength is not necessarily obtained compared to general nidistomers.

[Means for solving problems]

With the aim of expanding the uses of polyolefin-based urethanes, the present inventors, as a result of intensive studies, found that when producing a urethane entomer by reacting a polyolefin polyol with a polyisocyanate compound, hydrogen of polyhydroxybutadiene with a specific structure was used. The present invention was achieved by discovering that a soft elastomer composition with significantly improved mechanical properties can be obtained by using additives and filling an inorganic filler.

That is, the gist of the present invention is a polyolefin polyol obtained by hydrogenating qo% or more of the double bonds of a polyhydroxypolybutadiene having 70 or more (,)/, co-bonds; (b) a polyisocyanate compound; , and (c)
(-), (b) 9 total amount per 100 parts by weight fit ~ 3
00 parts by weight of inorganic filler.

Furthermore, if necessary, (-), (b) total 1io
o parts by weight of TBiO to JOO parts by weight of plasticizer.

The present invention is a soft nidistomer composition that is flexible and has excellent mechanical strength and has a surface hardness of 90 Å or less as defined by JIB K-6301.

The present invention will be explained in more detail below.

The polyolefin polyol (-) used in this invention 14 has a number average molecular weight of SOO to J O,00.
Hydrogenated products of polyhydroxypolybutadiene in the range 0 are preferred.

The polyhydroxypolybutadiene referred to herein is a polybutadiene having more than 1 hydroxyl group per molecule, which is synthesized by a known polymerization method. - For example, α,ω-dihydroxypolymer can be obtained from K by polymerizing sibutadiene by an anionic polymerization method using sodium naphthalene as an initiator, then adding ethylene oxide to the terminal and hydrolyzing it in Kitakami. Butadiene is mentioned.

In addition, at this time, it is also possible to replace a part of butadiene with other hexamers. Examples of monomers that can be used include dienes such as isoprene, and vinyl heptamers such as styrene, acrylonitrile, and methyl (meth)acrylate. It is preferable that the amount of these copolymerized components is 30 weight or less based on the total monomer t.

Moreover, the hydrogenation reaction of the polyhydroxybutadiene is
Using known catalysts such as nickel, ruthenium, and platinum,
It may be carried out in a conventional manner under hydrogen pressure.

Here, from the viewpoint of heat resistance and weather resistance, it is desirable that the hydrogenation rate is qo% or more of double bonds, preferably 91% or more. Moreover, the structure of this polybutadiene polyol is as follows: 1. It is desirable that the bonding ratio is at least 0%, preferably at least 0%. A polyolefin polyol produced from a polybutadiene polyol within this range is simply reacted with a polyisocyanate compound to form a polyurethane elastomer.

However, by filling an inorganic filler as in the present invention, the mechanical strength can be specifically and significantly improved. Ru.

Note that when using a polyolefin polyol made from polybutadiene with 70% or less of co-bonds, a urethane elastomer with considerably high mechanical strength can be obtained without using an inorganic filler; However, no significant improvement in mechanical properties as in the present invention was observed, and when a flexible formulation with a hardness of JIg or less was used.

In terms of the balance between hardness and mechanical properties, only inferior elastomers can be obtained.

In the present invention, a part of the polyolefin polyol can also be replaced with another polyol. Examples of other polyols include ethylene glycol, Coethyl/
, lower polyols such as J-hexanediol, glycerin, and trimethylolpropane, and polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

Examples include polyester polyols such as polycaprolactone polyol and castor oil polyol, and polyols obtained by adding alkylene oxide to ethylenediamine, trimethylolpropane, and the like.

The amount that can be used is the 0-SO weight of the polyolefin polyol.

Examples of the polyisocyanate compound (b) used in the present invention include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (fll) I), inphorone diisocyanate ( Diisocyanates such as IPDI), polyfunctional incyanate compounds such as polymeric diphenylmethane diisocyanate, or diincyanates such as TDI and HDI are isocyanurates.

Examples include those modified and polyfunctionalized by reactions such as urethane and billet.

Further, these isocyanates can be used as they are or as a prepolymer in which a portion is reacted with a polyol in order to improve toxicity and workability.

The amount of the inocyanate compound to be used is in the range of Q, t to /J, preferably 0.9 to 8, as the ratio NC010H of the isocyanate equivalent to fK of the hydroxyl group of the polyol.

Examples of inorganic fillers include carbon black, Merck, carbonic acid, lucium, and silica. Among them, carbon black and silica have a remarkable effect on improving strength, and calcium carbonate has a remarkable effect on improving elongation.

The amount of the filler that can be added is from 5 to 300 parts by weight, preferably from 10 to 10 parts by weight, per ioo parts by weight of the resin solid content, which is the total amount of polyol and incyanate compound. 00 parts by weight. If the amount added is less than S parts by weight, no sufficient effect of improving mechanical properties can be expected, and if it exceeds 300 parts by weight, the viscosity will be high, which is undesirable in terms of workability.

There are no particular restrictions on the method of mixing these fillers with the polyol or prepolymer component, but three rolls are used to obtain a sufficient dispersion state.

It is desirable to use a device with high shear stress, such as a kneader.

In addition, in order to prevent foaming during curing, it is desirable to dry these fillers sufficiently in advance.

Furthermore, a plasticizer can be added to the nidistomer of the present invention in order to adjust the hardness and improve workability.

Examples of the plasticizer include paraffinic, naphthenic, and aromatic mineral oils commonly used in the rubber industry, synthetic oils such as alkylbenzene and alkylnaphthalene, and ester plasticizers such as dioctyl heptatarate and dioctyl adipate.

The amount of plasticizer added is preferably the resin solid content.

That is, the total of (,), (b) f1100 parts by weight 1
)tO~”300 parts by weight, more preferably 20-
/10 parts by weight. If the amount of plasticizer is less than this range, sufficient workability may not be obtained at room temperature, and if it exceeds this range, the plasticizer may ooze out from the cured product.

The resin composition of the present invention contains, in addition to the above-mentioned components.

Catalysts and stabilizers commonly used in the urethane industry and rubber industry can be added as necessary.

By combining the above components, an elastomer composition having arbitrary mechanical properties and workability can be obtained.
The hardness of the cured product is 90 or less according to the mu standard specified by JI8 K-1, 30/, preferably 0 or less. In general, the strength of an elastomer can be very strong if it is blended with high hardness; however, in the cured product of the present invention, if it exceeds this range, only an inferior product can be obtained in terms of the balance between hardness and strength.

〔Example〕

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

The scope of the present invention is not limited by these Examples unless the gist of the present invention is exceeded.

In addition, in the following Examples and Comparative Examples, the mechanical properties of the cured products, such as hardness, tensile strength, elongation, etc., are in accordance with JIS K
−1,30/K was therefore measured.

Example 1 Polyolefin polyol manufactured by Mitsubishi Kasei Co., Ltd. (obtained by hydrogenating polybutadiene polyol containing about 90% of l and 2 bonds. Polyolefin polyol: hydroxyl group to
, t o t w @ 11/)) 100f and 2. Dirt Relene Diisocyanate/! , 2f was reacted with goc for 6 hours to obtain a prepolymer.

Each ounce of this prepolymer was sufficiently dried in advance, and 9 carbon black N---〇 (Diaplatz ^3 Ri? manufactured by Mitsubishi Kasei Corporation) was blended and thoroughly kneaded with a three-roll mill.Furthermore, this composition was mixed with Voliteya HA Yu. ?, Adeka Kuod.

-A Asahi Denka Co., Ltd., ethylenediamine-propylene oxide adduct, functional polyol) After adding and thoroughly mixing, the mixture was press-molded at 100° C. for 1 hour to create a cured product with a thickness of 100 cm.

Example 3 Per 100f of the prepolymer of Example 1, 1 liter of paraffin-based process oil P-CoQO manufactured by Kyodo Oil Co., Ltd. was used. , 6? Add and adjust the amount of carbon black added.
In addition to using f, a cured product was prepared by kneading and molding in exactly the same manner as in Example 1.

Examples D and S The inorganic filler was Aerosil! % -97s(
A cured product was prepared by cross-wiring and press molding in the same manner as in Example-1, except that hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd.) and calcium carbonate were used.

Comparative example 1. A cured product was prepared in exactly the same manner as in Example 1 except that no inorganic filler was added.

Comparative Example 3 Polyolefin polyol manufactured by Mitsubishi Kasei Co., Ltd., obtained by hydrogenating a polybutadiene polyol containing a polybutadiene polyol (approx.
ll/m@q/9-)/DO! On a three roll heated to ff0cK, modified diphenylmethane diisocyanate manufactured by MD Kasei Co., Ltd. (15 on m/' IJL incyanate equivalent weight, o) was added to i'.

m@q / f ) / ko? After adding and mixing thoroughly.

A cured product was prepared by hot pressing in the same manner as in the example.

Comparative Examples Dall ■ A cured product was prepared in exactly the same manner as in Comparative Example 3 except that Polytail HK, naphthenic process oil, and carbon black were kneaded in advance with tOC.

Obtained as described above. The mechanical properties of the cured product are summarized in Table/.

The mechanical properties of the cured product of the present invention are significantly improved by incorporating an inorganic filler.

As shown in Figure 1, a flexible and high-strength elastomer that exhibits excellent performance in the balance between hardness and strength can be obtained.

〔Effect of the invention〕

Conventionally, in polyester-based and polyether-based urethane elastomers, no improvement in mechanical properties has been observed even when inorganic fillers are blended.

Fillers were simply used as extenders to reduce costs.

On the other hand, the reinforcing effect of fillers is known in the case of urethane distomers mainly composed of polyhydroxypolydiene, but such systems have poor heat resistance and weather resistance due to unsaturated bonds, so it is difficult to actually The disadvantage is that the hardness gradually increases when used for a long period of time.

The object of the present invention is an elastomer made by blending an inorganic filler with polyurethane, which is a reaction product of a polyolefin polyol having a specific structure and a polyisocyanate compound.

Not only does it have a marked improvement in mechanical strength compared to systems that do not contain fillers, but its structure also provides superior heat resistance, weather resistance, moisture resistance, and hydrolysis resistance, making it suitable for various types of moisture proofing and
It has optimal performance as a waterproof sealant.

In addition, it exhibits fluidity or plasticity when heated at room temperature or relatively low temperature, and has good structural compatibility with hydrocarbon rubber, so it can be used as an adhesive for vulcanized rubber, making it extremely useful in industry. Useful.

[Brief explanation of the drawing]

FIG. 1 shows the relationship between hardness and tensile strength of a composition of the present invention. O is Examples 1 to 3. * represents Comparative Example 1I-4, respectively. Applicant Mitsubishi Chemical Industries, Ltd. Agent Patent Attorney For long diameter - (1 other person)

Claims (2)

[Claims] (1) (a) A polyolefin polyol obtained by hydrogenating 90% or more of the double bonds of polyhydroxypolybutadiene having 70% or more of 1 and 2 bonds, (b) a polyisocyanate compound, and (c) (a ), 5 to 100 parts by weight of the total amount of (b)
A soft elastomer composition comprising 300 parts by weight of an inorganic filler and having a surface hardness of 90A or less as defined in JIS K-6301. (2) Per 100 parts by weight of the total amount of (a) and (b), 1
The elastomer composition according to claim 1, which contains 0 to 300 parts by weight of a plasticizer.