JP2539445B2 - Isobutylene polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an isobutylene polymer having a specific reactive silicon group in the molecule.

[Prior Art] As a rubber-based polymer having a reactive silicon group, a propylene oxide-based polymer having a reactive silicon group at a molecular end is known, and it is cured by a humidity or the like even at room temperature to give a rubber elastic body. It has an interesting property of becoming However, the propylene oxide-based polymer has insufficient properties such as weather resistance, water resistance, and heat resistance, and its application may be limited.

[Problems to be Solved by the Invention] The present invention provides a propylene oxide-based polymer having a reactive silicon group at the molecular end, such as weather resistance, water resistance, and
This is done in order to improve defects such as insufficient heat resistance.

[Means for Solving Problems] In the present invention, when a polymer having a reactive silicon group at a molecular end is produced using an isobutylene-based polymer containing no polar element instead of the propylene oxide-based polymer, Not only can the propylene oxide-based polymer having a reactive silicon group at its molecular end be improved in terms of weather resistance, water resistance and heat resistance, but it can also be improved in properties such as electrical insulation and gas barrier properties. Was found based on the finding that at least one general formula (1): (In the formula, each of R ¹ and R ² is an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or (R ³ ) ₃ SiO- (R ³ is a monovalent hydrocarbon group having 1 to 20 carbon atoms and the three R ³ may be the same, a triorganosiloxy group represented by different may be), a number of R ¹ and b R ^{2 s} may be the same or different, R ¹ and R ² may be the same or different, and X is a hydroxyl group or a hydrolyzable group. When two or more are bonded, they may be the same or different, and a is 0, 1, 2 or 3,
b represents an isobutylene-based polymer having a reactive silicon group represented by 0, 1 or 2, and m is an integer of 0-18.

[Example] The polymer of the present invention is preferably a liquid having a number average molecular weight of about 500 to 30,000, more preferably about 1,000 to 15,000, and is a polymer mainly containing isobutylene units.

Mainly consisting of isobutylene units means that at least 50% (wt%, the same below), preferably 70% or more of the polymer are units derived from isobutylene, and other units constituting the polymer will be described later. The unit derived from the initiator used in the production of the isobutylene-based polymer, the unit derived from the cationic polymerizable monomer used in the production of the isobutylene-based polymer, and the like are included.

When the number average molecular weight of the polymer of the present invention is less than 500,
The ratio of isobutylene units contained in the polymer may not be the main component, and the low gas permeability, good weather resistance, electrical characteristics, and heat resistance, which are caused by the isobutylene-based polymer, are less likely to occur. Further, when the number average molecular weight exceeds 30,000, there is no problem as the characteristics of the polymer, but there is a problem that the viscosity becomes too high and it is not practical and it is not practical,
Liquid substances of about 1,000 to 15,000 are preferable because they are easy to handle.

The polymer of the present invention has at least one, preferably 1.2 to 4 general formula (1) per molecule: (In the formula, each of R ¹ and R ² is an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or (R ³ ) ₃ SiO- (R ³ is a monovalent hydrocarbon group having 1 to 20 carbon atoms and the three R ³ may be the same, a triorganosiloxy group represented by different may be), a number of R ¹ and b R ^{2 s} may be the same or different, R ¹ and R ² may be the same or different, and X is a hydroxyl group or a hydrolyzable group. When two or more are bonded, they may be the same or different, and a is 0, 1, 2 or 3,
The reactive silicon group represented by b is 0, 1 or 2, and m is an integer of 0 to 18) is present at the terminal.

Specific examples of the hydrolyzable group of X in the general formula (1) include, for example, a hydrogen atom, a halogen atom such as a chlorine atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amido group, an aminooxy group, Examples thereof include commonly used groups such as mercapto group and alkenyloxy group. Among these, an alkoxy group is particularly preferable because it has mild hydrolyzability and is easy to handle.

The number of X in the general formula (1) is 1 or more, and when X is less than 1, the properties of the polymer of the present invention such as curability cannot be sufficiently obtained. The number of X is preferably 2 or more, and particularly 2 to 3 from the viewpoint of the physical properties of the cured product.

The number of silicon atoms forming the reactive silicon group may be one or two or more, but in the case of silicon atoms connected by a siloxane bond or the like, it is usually up to 19. Is preferred.

When the number of reactive silicon groups represented by the general formula (1) is less than 1 per molecule, curability becomes insufficient,
It becomes difficult to exhibit good rubber elasticity behavior. The reactive silicon group is present at the terminal of the molecule, and in this case, the amount of effective network chains of the isobutylene-based polymer component contained in the cured product to be formed is large, resulting in a rubber-like product with high strength and high elongation. A cured product is easily obtained. Particularly preferred is a polymer having a linear polymer molecule and having reactive silicon groups at both ends.

Preferable specific examples of R ¹ , R ² and R ³ include lower hydrocarbon groups such as methyl group and ethyl group.

The isobutylene polymer having a reactive silicon group of the present invention has good weather resistance, water resistance and heat resistance, and further has excellent electric insulation and gas barrier properties. In particular, when the isobutylene-based polymer having a reactive silicon group of the present invention does not contain any unsaturated bond which is not an aromatic ring in the molecule, the polymer of the present invention contains an oxypropylene-based polymer or another unsaturated bond. Compared to the organic polymers that it has,
The weather resistance is remarkably improved. Further, since the polymer of the present invention has a hydrocarbon-based polymer, it has good water resistance, and once the surface is cured, the inside can be kept uncured so that excellent adhesion performance to various substrates is obtained. It can be used as a so-called mastic type sealant having

 Next, a method for producing the polymer of the present invention will be described.

The isobutylene-based polymer forming the skeleton of the isobutylene-based polymer having a specific reactive silicon group in the molecule of the present invention is produced by a cationic polymerization method containing an isobutylene monomer as a main component.

In the polymerization, in addition to the isobutylene monomer contained in the isobutylene-based polymer of the present invention in an amount of 50% or more, preferably 70% or more, a cationically polymerizable olefin having 4 to 12 carbon atoms, a conjugated diene, or a vinyl ether is used. , Aromatic vinyl compounds, vinylsilanes, allylsilanes and the like can be copolymerized. Specific examples of such a copolymer component include, for example, 1-butene, 2-butene, 2-methyl-1-butene, 3-methyl-1-butene, pentene, 4-methyl-1-pentene, hexene,
Vinyl cyclohexane, butadiene, isoprene, methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, styrene, α-methylstyrene, dimethylstyrene, monochlorostyrene, dichlorostyrene, β-pinene, indene, vinyltrichlorosilane,
Vinylmethyldichlorosilane, vinyldimethylchlorosilane, vinyldimethylmethoxysilane, vinyltrimethylsilane, divinyldichlorosilane, divinyldimethoxysilane, divinyldimethylsilane, 1,3-divinyl-
1,1,3,3-Tetramethyldisiloxane, trivinylmethylsilane, tetravinylsilane, allyltrichlorosilane, allylmethyldichlorosilane, allyldimethyldichlorosilane, allyldimethylmethoxysilane, allyltrimethylsilane, diallyldichlorosilane, diallyl Examples thereof include dimethoxysilane, diallyldimethylsilane, γ-methacryloyloxypropyltrimethoxysilane and γ-methacryloyloxypropylmethyldimethoxysilane.

In the cationic polymerization, an acid such as H ₂ SO ₄ , CCl ₃ CO ₂ H, or a Friedel-Crafts catalyst such as SnCl ₄ or TiCl ₄ may be used as an initiator, but it has a functional group at most of its molecular terminals. From the point that a polymer can be produced, US Pat.
It is preferably produced by the following inifer method described in Japanese Patent No. 4276394.

What is the Inifer method? (In the above formula, Y is a halogen atom, R ^{4 to} R ⁷ are hydrogen atoms, a lower alkyl group or a phenyl group, R ⁸ is a divalent hydrocarbon group, and R ^{9 to} R ¹² are monovalent ones having 1 to 20 carbon atoms. Hydrocarbon groups of R ¹³ , R
¹⁴ is a hydrogen atom, a monovalent hydrocarbon group or a halogen atom having 1 to 20 carbon atoms, never both R ^13, R ¹⁴ is a halogen atom, and the combination of R ¹³ and R ¹⁴ Neither 0 nor 1 is a halogen atom or a hydrogen atom.
A compound having a structure such as BCl ₃ , SnCl ₄ , TiCl ₄ , and SbCl with organohalogen compounds that can generate multiple stable carbon cations such as
₆ , a cationic polymerization method using a combination with a Friedel-Crafts acid catalyst such as FeCl ₃ and AlCl ₃ as a polymerization co-initiator.

In the inifer method, saturated hydrocarbon solvents such as ethane, propane, butane, pentane and hexane, methyl chloride, methylene chloride and 1,1-
To produce a polymer having a halogen atom in the organohalogen compound at a molecular terminal by polymerizing the above-mentioned cationically polymerizable monomer in a halogenated hydrocarbon solvent such as dichloroethane or a mixture thereof. You can

To give an example of the Inifer method, And BCl ₃ are used as a polymerization co-initiator and the isobutylene monomer is polymerized in methylene chloride at −70 ° C. Polymers having groups can be produced. Furthermore, at both ends By treating a polymer having a group with a strong base such as t-BuOK, it is possible to selectively carry out the dehydrochlorination reaction, and to terminate both ends of the molecule. It can be converted into an isobutylene-based polymer having a group. This polymer can be suitably used for hydrosilylation reaction as described later.

As a method for introducing a reactive silicon group into the molecule of the isobutylene polymer used in the present invention, the general formula (2) obtained as described above: And an isobutylene-based polymer having at least one unsaturated bond represented by the formula (3): (In the formula, R ₁ , R ₂ , X, a, b and m are the same as above) and a hydrogenated silicon compound represented by, for example, H ₂ PtCl
₆ / 6H ₂ O, Pt metal, RhCl (PPh ₃ ) ₃ , RhCl ₃ , Rh / Al ₂ O ₃ , RuCl ₃ , IrC
A method in which a compound such as l ₃ , FeCl ₃ , AlCl ₃ , PdCl ₂ · 2H ₂ O, NiCl ₂ , and TiCl ₄ is used as a catalyst and is introduced at the molecular end by a so-called hydrosilylation reaction is useful.

The hydrosilylation reaction is generally carried out in a temperature range of 0 to 150 ° C., and n-pentane, n-hexane, n-heptane, benzene, toluene, and the like may be added as necessary such as adjusting the reaction temperature and adjusting the viscosity of the reaction system. A solvent such as xylene may be used.

At least one unsaturated bond represented by the general formula (2) is used.
Among the polymers contained in individual molecules, the isobutylene-based polymer obtained by the above-mentioned inifer method is It is preferable because it has a group. At the end of the molecule The isobutylene-based polymer having a group has Introduced as many groups as possible, reactive silicon groups were introduced more at the molecular ends during the hydrosilylation reaction,
It is preferable because it reduces the number of terminals that are not involved in curing, and it should be 70% or more of the terminals. Those in which a group is introduced are particularly preferable. Per molecule The average number of groups is preferably in the range of 1.4 to 4.5. If this number is less than 1.4, it is difficult to introduce a reactive silicon group into all unsaturated double bonds.
In some cases, it may not be possible to introduce at least one reactive silicon group at the molecular end, and the curability of the polymer after the introduction of the reactive silicon group may be insufficient. Further, in the case of a cured product of a polymer having more than 4.5 reactive silicon groups introduced in one molecule, the rubber-like property may be insufficient. Therefore, before introducing the reactive silicon group. The number of unsaturated double bonds of is preferably up to 4.5 in one molecule.

Specific examples of the hydrogenated silicon compound represented by the general formula (3) include, for example, trimethoxysilane, triethoxysilane, methyldimethoxysilane, phenyldimethoxysilane, 1,3,3,5,5,7,7-heptamethyl. , Alkoxysilanes such as -1,1-dimethoxytetrasiloxane; acyloxysilanes such as methyldiacetoxysilane and trimethylsiloxymethylacetoxysilane; bis (dimethylketoxymate) methylsilane, bis (cyclohexylketoxymate) methylsilane, Ketoxymate silanes such as bis (diethylketoximate) trimethylsiloxysilane; dimethylsilane, trimethylsiloxymethylsilane, 1,1,3,3-tetramethyldisiloxane, 1,3,5-trimethylcyclotrisiloxane, etc. Have two or more Si-H bonds in the molecule Idoroshiran the like;
Examples thereof include alkenyloxysilanes such as methyldi (isopropenyloxy) silane, but are not limited thereto. Also, trichlorosilane, methyldichlorosilane, in which X is a halogen atom such as a chlorine atom,
When chlorosilanes such as dimethylchlorosilane and trimethylsiloxydichlorosilane are used, the hydrosilylation reaction proceeds more easily than other silicon hydride compounds.
However, the obtained polymer produces hydrogen chloride gas or hydrochloric acid during condensation curing, and the produced chlorine ion acts as a catalyst for the condensation reaction of the reactive silicon group, which adversely affects the storage stability of the polymer. There is a gap. In such a case, the halogen atom such as the chlorine atom of the chlorosilyl group of the obtained polymer is converted into an alkoxy group, an acyloxy group, an aminooxy group, an alkenyloxy group, a hydroxyl group or the like, and the obtained isobutylene is obtained. The system polymer does not have the above-mentioned adverse effects, and the hydrosilylation reaction easily occurs. Of these, alkoxy groups are particularly preferable because they have mild hydrolyzability and are easy to handle.

The polymer of the present invention is crosslinked and hardened by forming a siloxane bond to form a rubber-like material. Therefore, this polymer can be preferably used as an adhesive, a pressure-sensitive adhesive, a paint, a sealant, a waterproofing agent, a spraying agent, a molding material, a cast rubber material and the like.

When using the polymer of the present invention, various additives are added as necessary. Examples of such additives include known curing catalysts that accelerate the silanol condensation reaction, physical property modifiers such as silane compounds, various fillers, plasticizers,
Water, anti-aging agent, ultraviolet absorber, lubricant, pigment, foaming agent,
Examples thereof include adhesion promoters. Next, the isobutylene polymer of the present invention will be described based on Examples.

Example 1 An isobutylene polymer having an isopropenyl group and a molecular weight of about 5,000 at a ratio of about 92% at both ends (a product produced by an inifer method using paradicumyl chloride and boron trichloride as an initiator was dehydrochlorinated. 20 g and toluene 1 g are weighed in a 500 ml four-necked flask and heated to 90 ° C.
It was degassed under reduced pressure for 2 hours. Next, at room temperature under a nitrogen atmosphere, dry heptane 120 ml, methyldichlorosilane 1.15 g and chloroplatinic acid catalyst solution 0.1 ml (H ₂ PtCl ₆ .6H ₂ O 1 g were dissolved in 1,2-dimethoxyethane 9 g and ethanol 1 g. Solution) and then reacted at 90 ° C. for 12 hours.

When the amount of residual isopropenyl group of the isobutylene polymer in the reaction solution was quantified by IR spectrum analysis, almost no absorption of isopropenyl group (1640 cm ^-1 ) was observed and it was not remained.

Next, 21.2 g of methyl orthoformate and 6.4 g of methanol were added and reacted at 70 ° C. for 3 hours. At this point, the pH of the reaction system became about 7 and became neutral. After the volatile components were distilled off under reduced pressure, 50 ml of hexane was added to the remaining components and the contents were well stirred to remove insolubles by excess. Hexane is distilled off from the liquid, and An isobutylene polymer having groups was obtained.

When the obtained polymer was analyzed by NMR method, it was found that about 80% of the molecular ends were It was found that the group was introduced.

The NMR chart of the obtained polymer is shown in FIG. 1 for reference.

At the end of the obtained molecule 100 parts of a group-containing isobutylene polymer, 50 parts of hydrogenated polybutene (made by Idemitsu Petrochemical Co., Ltd., trade name Polybutene OH) as a plasticizer, hindered phenolic antioxidant (made by Ouchi Shinko Chemical Co., Ltd., product Name Nocrac NS-6) 1
Part, 2 parts of dibutyltin dilaurate curing catalyst are weighed and mixed well, and then poured into a mold having a thickness of about 3 mm,
After curing at room temperature for 4 days and at 70 ° C. for 10 days, a cured product was obtained.

When the cured product was cut out, about 1 mm of the surface layer was cured, but the inside was a mastic type cured product which was not cured.

Also, at the end of the obtained molecule 100 parts of the group-containing isobutylene polymer, 0.5 part of water and 50 parts of toluene were well stirred to form a uniform toluene solution. After pouring this solution into a mold with a thickness of about 3 mm and curing it at room temperature for 1 day and further at 50 ° C for 4 days, devolatilize it at 50 ° C under a reduced pressure of 2-3 mmHg for 2 hours to completely evaporate toluene. did.

The obtained cured sheet is a sunshine carbon arc weather meter (120 minutes cycle, spray 18 minutes)
The surface of the sheet was not deteriorated at all, and the sheet itself was made into resin,
There was no softening. Further, in order to measure the heat resistance of the cured product sheet produced in the same manner, the cured product sheet was placed in a hot air dryer at 150 ° C., and changes in properties with time were observed. There was no change at 30 minutes, and there was some coloration even after 5 hours, but the surface tack was not increased at all, and neither resinification nor softening was observed.

Comparative Example 1 800 g of polypropylene oxide having an allyl ether group introduced at 97% of all terminals and having an average molecular weight of 8000 was placed in a pressure resistant reactor equipped with a stirrer, and 19 g of methyldimethoxysilane was added.
Then, chloroplatinic acid catalyst solution (8.9 g of H ₂ PtCl ₆ .6H ₂ O was added to 18 ml of isopropyl alcohol and 160 m of tetrahydrofuran).
After adding 0.34 ml of a solution dissolved in 1 l), the mixture was reacted at 80 ° C. for 6 hours.

When the amount of residual silicon hydride groups in the reaction solution was quantified by the IR spectrum analysis method, almost no residue remained. When the silicon group was quantified by NMR,
About 85% of the molecular ends It turned out to be the basis.

Using the obtained polymer, a cured product sheet was prepared in the same manner as in Example 1, and the weather resistance was measured. The cured product sheet was already softened when exposed for 60 hours and partly flowed down. Furthermore, using a cured product sheet produced in the same manner,
When heat resistance was measured in the same manner as in Example 1, softening and melting occurred in 30 minutes, and further 5 hours later, decomposition further proceeded and volatilized.

[Effect of the Invention] When the isobutylene-based polymer of the present invention is used, weather resistance,
A cured product with excellent water resistance, heat resistance, electrical insulation and gas barrier properties can be obtained.

[Brief description of drawings]

FIG. 1 is an NMR spectrum showing the NMR analysis result of the polymer of the present invention obtained in Example 1.

Claims (3)

(57) [Claims] 1. At least one general formula (1) at the molecular end: (In the formula, each of R ¹ and R ² is an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or (R ³ ) ₃ SiO- (R ³ is a monovalent hydrocarbon group having 1 to 20 carbon atoms and the three R ³ may be the same, a triorganosiloxy group represented by different may be), a number of R ¹ and b R ^{2 s} may be the same or different, R ¹ and R ² may be the same or different, and X is a hydroxyl group or a hydrolyzable group. When two or more are bonded, they may be the same or different, and a is 0, 1, 2 or 3,
b is 0, 1 or 2, m is an integer of 0 to 18), and an isobutylene polymer having a reactive silicon group. 2. X in the general formula (1) is a hydrogen atom, a hydroxyl group,
An alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amido group, an aminooxy group, a mercapto group or an alkenyloxy group, and when X is 2 or more, they may be the same or different. The isobutylene-based polymer according to claim 1. 3. The isobutylene polymer according to claim 1, wherein X in the general formula (1) is an alkoxy group.