JP2647432B2 - New liquid polymers and compositions - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is a novel liquid polymer which is excellent in operability and whose cured product has excellent heat resistance, weather resistance, water resistance, adhesiveness and rubber elasticity. And compositions containing the same.

[Conventional technology]

2. Description of the Related Art Conventionally, polyurethanes made of polyester and polyether-based polyols have been widely used for applications such as sealing materials, coating materials, and potting materials. However, conventional polyester and polyether-based polyols are not necessarily sufficient in water resistance and wet heat resistance due to ester and ether bonds present in the molecular chain. In recent years, polybutadiene-based polyols have come to be used, but these have improved water resistance and wet heat resistance, but are inferior in heat resistance and weather resistance due to carbon-carbon double bonds in the main chain. . In order to improve the heat resistance and weather resistance, a method of hydrogenating the carbon-carbon double bond has been adopted. In the case of polybutadiene, the main chain is CH ₂ —CH ₂ by hydrogenating the structure of polyethylene. To show crystallinity, it becomes a solid at normal temperature, and when used as a urethane raw material, its operability is extremely poor when mixing with an isocyanate compound, a compounding agent such as a filler, and further molding. .

More recently, Attempts have been made to use a hydrogenated product of liquid polyisoprene having the following structure as a urethane raw material. However, as a result of studies by the present inventors, it was found that sufficient strength properties and adhesiveness could not be obtained.

[Problems to be solved by the invention]

The present invention provides a polyurethane having excellent water resistance, moisture resistance, heat resistance, weather resistance, sufficient strength properties and adhesiveness, and excellent operability such as mixing and molding when obtaining the polyurethane. The purpose is to provide raw materials for use.

[Means for solving the problem]

According to the present invention, the above object is achieved by a specific hydroxyl-containing liquid hydrogenated isoprene-butadiene copolymer or a composition containing the same.

That is, according to the present invention, the isoprene / butadiene weight ratio is in the range of 95/5 to 70/30, and the number average molecular weight is 700 to 7,
000, and relates to a liquid hydrogenated copolymer obtained by hydrogenating unsaturated bonds of a liquid isoprene butadiene copolymer having 1.5 to 4.0 hydroxyl groups in one molecule by 50% or more. The present invention relates to a composition containing a liquid hydrogenated copolymer and an organic polyisocyanate compound.

In the hydroxyl group-containing liquid isoprene-butadiene copolymer used in the present invention, the ratio of isoprene / butadiene must be in the range of 95/5 to 70/30 by weight.
When the amount of butadiene is less than the above range, there is no effect of improving the strength properties of urethane obtained by using the obtained hydrogenated product as a raw material, and when it exceeds the above range, it is attributed to the hydrogenated portion of butadiene. The crystallinity causes a solid state or a remarkable increase in viscosity, which impairs operability, which is not preferable.

The liquid isoprene-butadiene copolymer having a number average molecular weight of 700 to 7,000 is used. When the number average molecular weight is less than 700, the polyurethane obtained using the hydrogenated product does not have good physical properties. On the other hand, when it exceeds 7,000, the copolymer and its hydrogenated product do not show good fluidity, and the operability in obtaining a polyurethane is extremely deteriorated, which is not preferable. From this viewpoint, the number average molecular weight needs to be within the above range, and is particularly preferably in the range of 1,000 to 5,000.

Hydroxyl-containing liquid isoprene-butadiene copolymer is 1
It is necessary to have 1.5 to 4.0 hydroxyl groups in the molecule.
When the number of hydroxyl groups is less than 1.5, sufficient crosslinking cannot be carried out in the polyurethane using the hydrogenated product, and the strength properties become insufficient. If it exceeds 4.0, the crosslinked density becomes too high and a cured product exhibiting good elasticity cannot be obtained. Therefore, the amount of the hydroxyl group needs to be in the above range, and particularly preferably in the range of 1.8 to 3.0.
The hydroxyl group may be at the terminal of the molecular chain or at the end of the chain, but a compound having at least one terminal at the terminal is more preferably used. Such a hydroxyl group-containing liquid isoprene-butadiene copolymer can be obtained by a known method.
For example, a mixture of isoprene and butadiene is converted to hydrogen peroxide,
An azo compound having a hydroxyl group (for example, 2,2'-azobis [2-methyl-N- (2-hydroxyethyl) -propionamide) or the like) or a peroxide having a hydroxyl group (for example, cyclohexanone peroxide or the like) is used as a polymerization initiator. 0.1 to 50 mol% based on isoprene monomer
The hydroxyl group-containing liquid isoprene-butadiene copolymer can be obtained by using the copolymer in the above range and subjecting it to radical copolymerization.

In addition, a catalyst such as naphthalenedilithium or m-dilithiohexylbenzene is used per 100 parts by weight of isoprene monomer.
The mixture of isoprene and butadiene is anionically polymerized using 0.1 to 5 parts by weight, and after the polymerization is completed, 1 to 500 mol of ethylene oxide, propylene oxide or the like is added to 1 mol of the polymerization catalyst, and 0.1 to 50 at normal temperature to 200 ° C. Hydroxy group-containing liquid isoprene-butadiene can also be obtained by reacting for hours. This reaction can be carried out without solvent, but it is often preferable to use a solvent,
Thereby, the reaction can be easily controlled. In this case, the same solvent as used in the polymerization is used.

In both cases of radical polymerization and anionic polymerization, it is necessary to use a solvent inert to the catalyst. Examples of the solvent in the case of radical polymerization include alcohols such as ethanol and propanol, and aliphatic and alicyclic hydrocarbons such as hexane, heptane and cyclohexane, and aromatic hydrocarbons such as toluene. In the case of anionic polymerization, aliphatic hydrocarbons such as pentane and hexane, alicyclic hydrocarbons such as cyclohexane, and aromatic hydrocarbons such as benzene and toluene are used.

The amount of the solvent can be arbitrarily determined, but is preferably 80% or less of the entire polymerization system in view of efficiency.

The conditions for carrying out the polymerization are not particularly limited, but any of the polymerization methods can be carried out within a range of 0 ° C. to 200 ° C. for about 0.1 to 100 hours.

When copolymerization is performed, the form of copolymerization of isoprene and butadiene is preferably random copolymerization. In the case of block copolymerization, the block chain length of butadiene is
It is necessary to make it short so that it does not show crystallinity after hydrogenation, and it is preferable that the number of butadiene units be 10 or less.

A liquid isoprene-butadiene copolymer having a hydroxyl group at the terminal of the molecular chain can be obtained by the above method, but a copolymer polymerized by a radical catalyst having no hydroxyl group, or a hydroxyl group is introduced after anionic polymerization. Using a copolymer obtained without a reaction, for example,
A copolymer having a hydroxyl group introduced into a side chain by the method shown in 16003 or the like can also be used.

In the present invention, the liquid isoprene-butadiene copolymer is used after hydrogenation. At this time, it is necessary to hydrogenate at least 50% of the carbon-carbon double bonds in the copolymer.

If the degree of hydrogenation is less than 50%, the polyurethane obtained by using the same has a problem in that heat resistance or weather resistance due to heat or light due to double bonds is reduced. From this viewpoint, the hydrogenation rate needs to be 50% or more, preferably 80% or more, and more preferably 90% or more. Hydrogenation of the copolymer can be performed using a known method. For example, a method of performing catalytic hydrogenation using a Ziegler-based homogeneous catalyst or a solid heterogeneous catalyst is employed.

When a homogeneous catalyst is used, a saturated hydrocarbon such as hexane or cyclohexane or an aromatic hydrocarbon such as benzene, toluene, or xylene is used as a solvent, and a reaction pressure of normal temperature to 150 ° C. and a hydrogen pressure of normal pressure to 50 kg / cm ² . A hydrogenation reaction is carried out. As the homogeneous catalyst, a Ziegler catalyst or the like obtained by combining a transition metal halide with an alkylated product such as aluminum, alkaline earth metal or alkali metal is used in an amount of about 0.01 to 0.1 mol% per double bond of the polymer. The reaction is usually completed in 1 to 24 hours.

When a heterogeneous catalyst is used, saturated hydrocarbons such as hexane and cyclohexane, aromatic hydrocarbons such as benzene and toluene xylene, ethers such as diethyl ether, THF, and dioxane; alcohols such as ethanol and isopropanol; The hydrogenation reaction is carried out at a reaction temperature of normal temperature to 200 ° C. under a hydrogen pressure of normal pressure to 100 kg / cm ^{2 using} a mixed system of as a solvent. As a heterogeneous catalyst, a catalyst such as nickel, cobalt, palladium, platinum, rhodium, ruthenium alone, or silica, diatomaceous earth,
It is used by being supported on a carrier such as alumina or activated carbon, and its amount is suitably 0.5 to 10% by weight based on the weight of the polymer. The reaction is usually completed in 1 to 48 hours.

A composition using the hydrogenated copolymer, which is another object of the present invention, is a composition comprising the hydrogenated copolymer and an organic polyisocyanate compound having two or more isocyanate groups in one molecule. Things. This composition is made into polyurethane by crosslinking and curing, and is used for various purposes. As the organic polyisocyanate compound used here,
For example, tolylene diisocyanate, diphenylmethane diisocyanate, modified diphenylmethane diisocyanate, phenylene diisocyanate, dicyclohexylmethane diisocyanate and the like can be mentioned as examples. When curing, a method of mixing and curing a hydrogenated liquid isoprene-butadiene copolymer and a polyisocyanate compound (one-shot method) or a method of mixing a hydroxyl group of a hydrogenated liquid isoprene-butadiene copolymer with an isocyanate group of a polyisocyanate compound Are preliminarily reacted to form a copolymer having an isocyanate group, and this is cured using a curing agent (prepolymer method).

In the case of the one-shot method, the hydroxyl group (OH) and the isocyanate group (NCO) in the hydrogenated copolymer are NCO / OH =
It is used in the range of about 0.5 to 5.0. If the ratio is less than 0.5, the cured product will not have sufficient strength, while if it exceeds 5, the crosslink density will be too high to obtain a cured product having sufficient elasticity. This ratio is more preferably from 0.8 to
It should be in the range of 2.0.

At the time of curing, it is also possible to use a polyol and a polyamine compound in addition to the polyisocyanate compound. The amount of the polyol or polyamine compound used is not particularly limited, but is used in the range of 1 to 250 parts by weight based on 100 parts by weight of the liquid copolymer.

According to the prepolymer method, the NCO / OH molar ratio is 2.0
Performed in the range of ~ 5.0. If the ratio is less than 2.0, unreacted hydroxyl groups remain, which causes problems such as a significant increase in viscosity or hardening during the reaction and hardening during storage. Conversely, if it exceeds 5.0, the cured product loses its rubber elasticity. In some cases, after the reaction using more NCO, a method of removing excess isocyanate compound by means such as reducing the pressure may be used. The reaction temperature in the first half of the prepolymer method is from room temperature to 200 ° C., and the reaction time is from 0.1 to 50 hours. At this time,
Compounds such as tin and lead can also be used as catalysts.

The hydrogenated liquid isoprene-butadiene copolymer containing isocyanate groups obtained by the prepolymer method is water,
Cross-linking using polyol compounds, polyamine compounds, etc.
Hardened and used. When these are used as a cross-linking agent, they are used in a molar ratio of hydroxyl groups or amino groups to isocyanate groups (OH or NH ₂ / NCO) in the range of 0.5 to 5.0.

Here, in either the prepolymer method or the one-shot method, the polyol compound is 1,4-butanediol, pentanediol, hexanediol, ethylene glycol, propylene glycol, or the like, and the polyamine compound is tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenyl and the like are used.
In addition, in any one of the one-shot method and the prepolymer method, various compounding agents used when preparing ordinary polyurethane can be added and used. Examples thereof include reinforcing agents such as carbon black, silica, and calcium carbonate, fillers, phenol-based or amine-based anti-aging agents, rosin-based resins for improving adhesion and adhesion, terpene-based resins, and petroleum-based resins. Examples include tackifier resins, softeners represented by naphthene-based, paraffin-based, and aroma-based process oils, and plasticizers such as dioctyl phthalate, dibutyl phthalate, and diallyl phthalate. The amounts of these are not particularly limited as long as the objects and effects of the present invention are not impaired, and are appropriately determined according to the purpose.However, usually, the hydrogenated liquid isoprene-butadiene copolymer 100
0 to 500 parts by weight of a reinforcing agent / filler, 0 to 10 parts by weight of an antioxidant, 0 to 250 parts by weight of a tackifier resin, 0 to 300 parts by weight of a softener, and 0 It is appropriate to use ~ 300 parts by weight.

As conditions for curing, the prepolymer method, in any case of the one-shot method, from room temperature to 200 ° C.,
The reaction is preferably performed at a temperature of 80 to 150 ° C. for 0.1 to 20 hours.

Polyurethane obtained by using the copolymer or the composition according to the present invention is excellent in heat resistance, weather resistance, water resistance, moisture resistance and heat resistance, and also has sufficient strength properties, sealing material, coating material, It can be suitably used as a waterproof sheet, an electric material, a material for automobiles, and the like.

Example 1 A pressure-resistant reactor equipped with a stirrer was charged with 100 parts by weight of isopropanol, 170 parts by weight of isoprene, and 30 parts by weight of butadiene, and heated to 80 ° C. 16 g of a 50% hydrogen peroxide solution was added thereto, the temperature was raised to 120 ° C., and the mixture was reacted with stirring for 3 hours. After completion of the reaction, the reaction mixture was poured into a large amount of methanol to precipitate the product. The resulting precipitate was dried under reduced pressure to obtain a hydroxyl group-containing liquid isoprene-butadiene copolymer. The yield of the obtained product was 69%. As a result of product analysis,
Number average molecular weight is 2,850, hydroxyl group content is 2.18 / molecule,
The ratio of isoprene / butadiene was 86/14 as a result of analysis by an infrared absorption spectrum.

100 parts by weight of the obtained copolymer was dissolved in 50 parts by weight of cyclohexane, 10 parts by weight of Ru-C (Ru 5%) was added, and 50 kg /
The mixture was reacted at 120 ° C. for 6 hours under a hydrogen pressure of ² cm ² . The reaction product was further diluted with cyclohexane, and the catalyst was filtered. The filtrate was dried under reduced pressure to obtain a hydroxyl group-containing hydrogenated liquid isoprene-butadiene copolymer (I).

The product has a number average molecular weight of 2,910 and a hydroxyl content of 2.13.
Individual / molecule, iodine value was 1.2 g / 100 g. The hydrogenation rate based on the measurement result of the iodine value was 98%.

Comparative Examples 1 and 2 The reaction was carried out in the same manner as in Example 1 except that the ratio of isoprene / butadiene was 98 / 2,50 / 50, and the ratio of isoprene / butadiene was 98.
/ 2, number average molecular weight 2,760 hydroxyl content 2.21, iodine value 0.
9, isoprene / butadiene ratio 52/48, number average molecular weight 2,98
Hydrogen-containing hydrogenated liquid isoprene butadiene copolymers (II) and (III) having a hydroxyl group content of 2.16 and an iodine value of 1.4 were obtained, respectively.

The hydrogenated copolymer having an isoprene / butadiene ratio of 52/48 was solid at room temperature and had no fluidity at all.
The hydrogenation rate based on the measurement results of iodination is 97% (II) and 99%.
% (III).

Example 2 Using the hydroxyl group-containing hydrogenated liquid isoprene-butadiene copolymer obtained in Example 1 and Comparative Examples 1 and 2, a formulation was prepared according to the formulation shown in Table 1, and heated at 120 ° C. for 30 minutes. Table 1 shows the results of preparing a cured product and measuring the elongation in accordance with JIS K 6301.

The blend of the copolymer of Comparative Example 2 cannot be mixed at room temperature, and when mixed under heating, gelation occurs during mixing,
The following tests could not be used.

As shown in Table 1, it can be seen that the compositions according to the examples of the present invention have excellent strength properties.

Comparative Examples 3 and 4 Example 1 except that the amount of hydrogen peroxide used was 5 and 200 g.
In the same manner as described above, the isoprene butadiene mixture is polymerized to have a molecular weight of 11,000 and a hydroxyl group content of 580 of 1.580 respectively.
, 2.29 particles / molecule, and the ratio of isoprene butadiene is
83 / 17,85 / 15 isoprene / butadiene copolymer was obtained.

The obtained copolymer was dissolved in cyclohexane and hydrogenated using Ru-C (Ru 5%) as a catalyst in the same manner as in Example 1 to obtain a hydrogenated hydrogenated liquid isoprene-butadiene copolymer (IV), ( V) was obtained. The number average molecular weight of the product is 11,800,590, the hydroxyl content is 1.92, 2.28 / molecule,
The iodine values were 2.1 g / 100 g and 1.3 g / 100 g.

Comparative Example 5 Using the hydroxyl group-containing isoprene-butadiene copolymer obtained in Example 1, the reaction was carried out in the same manner as in Example 1, and the reaction was stopped halfway to obtain an iodine value of 210 g / 100 g and a degree of hydrogenation of 45.
% Hydroxyl group-containing hydrogenated isoprene butadiene copolymer (V
I got. The number average molecular weight was 2,890 and the hydroxyl group content was 2.16 / molecule.

Comparative Example 6 Using the hydroxyl group-containing hydrogenated isoprene-butadiene copolymer obtained in Comparative Examples 3, 4, 5 and Example 1, respectively, a blend was prepared according to the blend shown in Table 2, and heated at 120 ° C. for 30 minutes. Thus, a cured product was prepared, and the elongation was measured in accordance with JIS K6301. Furthermore, by heating the compositions of the copolymers obtained in Comparative Example 5 and Example 1 in an oven at 120 ° C. for one week, the change in shape was examined and the heat resistance was evaluated.

As shown in Table 2, the composition using the copolymer obtained in Comparative Example 3 does not show sufficient elasticity. The composition obtained from the copolymer obtained in Comparative Example 4 did not show any strength.

It can be seen that the copolymer having a low degree of hydrogenation exhibits a strong elongation value close to that of the hydrogenated one, but has a large deterioration after heating and is inferior in heat resistance.

[Effect of the Invention] The present invention provides a polyurethane having excellent water resistance, moisture resistance, heat resistance, weather resistance, sufficient strength properties and adhesiveness, and mixing and molding operations to obtain the polyurethane. A raw material for polyurethane having excellent properties is provided.

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Claims (3)

(57) [Claims] 1. A liquid isoprene-butadiene having a weight ratio of isoprene / butadiene in the range of 95/5 to 70/30, a number average molecular weight of 700 to 7,000, and having 1.5 to 4.0 hydroxyl groups in one molecule. A liquid polymer obtained by hydrogenating an unsaturated bond of a copolymer by 50% or more. 2. A liquid isoprene-butadiene having a weight ratio of isoprene / butadiene in the range of 95/5 to 70/30, a number average molecular weight of 700 to 7,000 and 1.5 to 4.0 hydroxyl groups in one molecule. A composition containing a hydrogenated liquid isoprene-butadiene copolymer obtained by hydrogenating an unsaturated bond of a copolymer by 50% or more and an organic polyisocyanate compound. 3. The molar ratio of the hydroxyl group (OH) in the hydrogenated liquid isoprene-butadiene copolymer to the isocyanate group (NCO) in the organic polyisocyanate compound is NCO / OH = 0.5 to 5.0.
The composition according to claim 2, which is: