JPH0343449A - One-component type moisture-curing resin composition - Google Patents

Abstract

PURPOSE:To obtain a one composition type moisture-curing resin composition, having terminal hydrolyzable silicon functional groups and the backbone chain consisting essentially of a polyether chain with oxyethylene groups, a high elongation and remarkably low curing rate without any deterioration in durability and suitable as sealing materials, etc. CONSTITUTION:A room temperature-curing resin composition, obtained by adding a hydrogenated silicon compound having hydrolyzable groups or functional groups convertible into the hydrolyzable groups to a polyester compound having terminal unsaturated groups in the presence of a platinum group catalyst and introducing terminal hydrolyzable groups and having 200-20000 molecular weight based on the number of one terminal functional group, hydrolyzable silicon functional groups expressed by the formula (R is monofunctional hydrocarbon, etc.; X is hydrolyzable group; R' is bifunctional organic group; (a) is 0, 1 or 2) and the backbone chain, consisting essentially of a polyether chain and containing oxyethylene groups in an amount of 2-40wt.% thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a one-component moisture-curable resin composition having hydrolyzable silicon terminations that cures at room temperature to a rubber-like material upon exposure to atmospheric moisture. .

[Prior Art] Thiocol-based, urethane-based, modified silicone-based, and silicone-based polymers are generally known as one-component room temperature curable polymers. Among them, modified silicone-based materials have relatively excellent durability and are useful as raw materials for sealing materials and the like.

Conventionally, as a method of obtaining modified silicone one-component type at low cost,
The method proposed in Japanese Patent Publication No. 45-36319 and Japanese Patent Publication No. 46-12154, and the method proposed in Japanese Patent Publication No. 46-30711 are known, but because they use low molecular weight hydroxyl-terminated polyether as raw material, The elongation of the cured product of the silicon-terminated polymer was so small that it was not satisfactory as a rubber elastic body.

In order to eliminate this drawback, Japanese Patent Application Laid-Open No. 50-149797
There is a method proposed in JP-A-50-156599, but it is extremely difficult to obtain a polymer having a narrow molecular weight distribution, and it also has the disadvantage that the viscosity increases. On the other hand, methods for producing high molecular weight polyoxyalkylene polymers with narrow molecular weight distribution are disclosed in JP-A-61-197631 and JP-B-59-15.
No. 336, US Pat. No. 3,929,505, etc.

However, generally high molecular weight polyoxyalkylene polymers were used. Warm-curable resin compositions having terminal hydrolyzable silicon groups have had the disadvantage that as the molecular weight increases, the elongation of the cured product increases, but the curing speed becomes significantly slower.

[Problems to be Solved by the Invention] The present invention has been made to solve the above-mentioned problems, and provides a one-component temperature-curable resin composition that has high elongation, significantly slows curing speed, and does not reduce durability. Regarding.

[Means for Solving the Problems] The present invention was made in order to solve the above-mentioned problems, and has a material that has greater elongation, a significantly slower curing speed, and almost no decrease in durability compared to conventional lano. A component-type moisture-curable resin composition is provided.

Molecular weight per number of terminal functional groups: 2.000 to 20.000
At the terminal end, the general formula: %Formula% Where, R is a monovalent hydrocarbon group or a halogenated hydrocarbon group X is a hydrolyzable group R' is a divalent organic group In the room temperature curable resin having a hydrolyzable silicon functional group, the main chain is essentially a polyether chain, of which 2 to 40% by weight of oxyethylene groups (OCI
Hz-). The resin having a terminal hydrolyzable silicon functional group of the present invention is basically disclosed in Japanese Patent Application Laid-open No. 50-14979.
7 and JP-A-50-156599. That is, a silicon hydride compound having a hydrolyzable group or a functional group that can be converted into a hydrolyzable group is added to a polyether compound having a terminal unsaturated group using, for example, a platinum group catalyst to introduce a terminal hydrolyzable group. It's a method. The polyether compound having a terminal unsaturated group is generally prepared by reacting the terminal hydroxyl group of a polyether polyol with an unsaturated group-containing halogen compound. Examples of polyether polyols that can be used in the present invention include polyoxyalkylene polyols and polytetramethylene glycol-terminated polyoxyalkylene-modified polyols. The molecular weight of is 3000~2
0000 is preferred. Outside these ranges, for example, if the molecular weight is low, the elongation of the cured product will be low, and if the molecular weight is high, curing will be extremely slow, making it impractical.

The present invention is characterized by containing oxyethylene dioxy groups (-QC:H2CH2) in an amount of 40% by weight or less of the polyether chain; This is achieved by using Such a polyoxyalkylene polyol can be easily produced by using part or all of ethylene oxide during ring-opening polymerization of alkylene oxide in the presence of an initiator. The content of the ethylenedioxy group is preferably 2 to 40% by weight of the polyoxyalkylene chain, more preferably 2 to 30% by weight, and most preferably 2 to 20% by weight. By containing an ethylenedioxy group, the moisture curing rate at room temperature is significantly improved and becomes faster, and the decrease in durability remains small. The polyoxyalkylene polyol synthesized by ring-opening polymerization of alkylene oxide used in the present invention can be synthesized by the method described in Japanese Patent Publication No. 59-15336, US Pat. No. 4,355,18, and US Pat. No. 4,721,818. The polyoxyalkylene polyols produced by these methods have a high molecular weight and a narrow molecular distribution,
This is preferable because the moisture-curable resin composition of the present invention can have a large elongation. In addition to ethylene oxide, at least one of propylene oxide and butylene oxide is preferably used as the alkylene oxide. Polyvalent initiators used in the production of polyoxyalkylene polyols include polyhydric alcohols, polyhydric phenols, polyamines, alkanolamines, and the like. Specifically, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1.
4-butanediol, 1,6-hexanediol, glycerin, trimethylolpropane, pentaerythritol, diglycerin, textulose, sucrose,
These include bisphenol A and ethylenediamine. These may be used alone or in combination of two or more. Particularly preferred are polyhydric alcohols, especially dihydric and trihydric alcohols. Boboxyalkylene polyol is also generally synthesized by ring-opening polymerization of alkylene oxide in the presence of an initiator using an alkali catalyst such as an alkali metal compound (alkali hydroxide) as a polymerization catalyst.
If the average molecular weight per hydroxyl group exceeds 3,000, side reactions will increase, making it impractical and therefore not suitable as a raw material for the present invention.

The hydrolyzable silicon-terminated polymer in the present invention has 50% or more and 100% or less of the terminal groups represented by the general formula: % Formula %. In the formula, R is a monovalent hydrocarbon group or a halogenated hydrocarbon group, and is an alkyl group or fluoroalkyl group having 8 or less carbon atoms, preferably 6 or less carbon atoms.

Particularly preferred are methyl group and ethyl group. X is a hydrolyzable group, such as a halogen atom, an alkoxy group, an acyloxy group, an amide group, an acid amide group, an aminooxy group, a ketoximate group, and the like. Preferred hydrolyzable groups are alkoxy groups, especially methoxy and ethoxy groups.

As Ro, a hydrocarbon group, particularly a trimethylene group, is preferable from the viewpoint of ease of production. a represents an integer of 0, 1, or 2, and is particularly preferably O or 1.

[Function] When the hydrolyzable silicon-terminated polymer in the present invention comes into contact with moisture, it becomes three-dimensional and hardens through a crosslinking reaction. The curing mechanism is that the hydrolyzable group X is first replaced with a hydroxyl group, and then this 5
iOH groups condense with each other to form crosslinks, forming siloxane bonds (
SL-0-3L) is formed or 5iOH group and Si
Either a siloxane bond and HX are formed by reaction with the X group, and curing occurs.

At this time, the rate of hydrolysis depends on the atmospheric temperature, relative humidity, type of hydrolyzable group, etc., but the oxyethylene group (-
It is presumed that when 0-CH, -CH2-) is present, the hydrophilicity increases, resulting in a -layer speed.

In the curing reaction, it is not necessary to use a curing accelerating catalyst. Curing accelerating catalysts include alkyl titanates, organosilicon titanates, metal salts of carboxylic acids such as tin octylate and dibutyltin dilaurate, amine salts such as nidibutylamine-2-ethylhexoate, and other acids. Using catalysts and basic catalysts. The catalyst can be added at any stage of polymer production.

The polymer of the present invention may further contain reinforcing agents, fillers, if necessary.
A plasticizer, anti-sagging agent, etc. may be included. Carbon black, finely powdered silica, etc. are used as reinforcing agents, and calcium carbonate, talc, clay, silica, etc. are used as fillers.
Plasticizers include dioctyl phthalate, dibutyl phthalate, dioctyl adipate, chlorinated paraffin, and petroleum plasticizers, and pigments include inorganic pigments such as iron oxide, chromium oxide, and titanium oxide, and organic pigments such as phthalocyanine blue and phthalocyanine green. Examples of anti-sagging agents include organic acid-treated calcium carbonate, hydrogenated castor oil aluminum stearate, calcium stearate, zinc stearate, and finely powdered silica.

The silicon-terminated polymers of the present invention can be suitably used as coating compositions and sealing compositions for buildings, aircraft, automobiles, etc., or the like.

[Example] The polyoxyalkylene polyols in Examples and Comparative Examples were synthesized using a cobalt zinc cyanide/glyme complex as a propylene oxide addition catalyst and sodium methoxide as an ethylene oxide addition catalyst.

Example 1 0.49 parts of sodium hydride was added to 100 parts of polyoxypropylene diol A, which had a molecular weight of 10,000, a total degree of unsaturation of 0.020 meq/g, and had a dipropylene glycol initiator containing 20% by weight of oxyethylene groups at the terminals. , and heated at 100° C. for 1 hour under a nitrogen stream. Cool this to 50°C, add 1.68 parts of allyl chloride, and heat for 6 hours.
Stirred. After cooling to room temperature, 300 parts of hexane and 1 part of magnesium silicate were added, stirred at room temperature for 30 minutes, filtered, and hexane was distilled off under reduced pressure to obtain terminal unsaturated group-containing polyoxyalkylene polymer A. ′ was obtained. The total unsaturation degree of this was 0.194 meq/g. To 100 parts of the obtained unsaturated terminal polyoxyalkylene polymer, 2.1 parts of methyldimethoxysilane and 1 part of chloroplatinic acid solution (50.05 parts) were added.
82PtC1,,6Hz01g/100ml isopropyl alcohol) was added and heated to 60°C for 8 hours, and unreacted methyldimethoxysilane was distilled off under reduced pressure to obtain a silicon-terminated modified product. 1 part of dibutyltin dilaurate as a curing catalyst was added to 100 parts of the silicon-terminated modified product to obtain a -component type room temperature curable composition A''.

Example 2 Using dipropylene glycol as an initiator, a polyoxyalkylene diol with a molecular weight of 2,000 containing 50% by weight of oxyethylene groups copolymerized with propylene oxide and ethylene oxide was used as a raw material, and propylene oxide was addition-polymerized to obtain a polyoxyalkylene diol with a molecular weight of 10,000 and total polymerization. Saturation degree 0.020m
eq/g of polyoxyalkylene diol B was obtained. 100 parts of polyoxyalkylene diol B and 0.49 parts of sodium hydride were added, and from 1.68 parts of allyl chloride, 101 parts of terminal unsaturated group-containing polyoxyalkylene polymer B'' was obtained by the method described in Example 1. The total unsaturation degree of this was 0.192 meq/g.
A silicon-terminated modified product was obtained by the method described in Example 1 from 00 parts of methyldimethoxysilane, 2.1 parts of methyldimethoxysilane, and 0.05 parts of chloroplatinic acid solution, and 1 part of dibutyltin dilaurate was added to 100 parts of this. In addition, a -component type room temperature curable composition B'' was obtained.

Example 3 Molecular weight 1000 using dipropylene gelcol as an initiator
From polyoxyalkylene diol C, which is a polymer of propylene oxide with a total unsaturation degree of 0.020 meq/g and 10% by weight of oxyethylene groups at the terminals, polyoxyalkylene diol C containing terminal unsaturated groups was prepared by the method described in Example 1. An alkylene polymer C' was obtained.

Further, according to Example 1, a silicon-terminated modified product having a terminal methyldimethoxysilyl group was obtained from C'. 1 part of dibutyltin dilaurate was added to 100 parts of the silicon-terminated modified product to obtain a -component type room temperature curable composition C''.

Example 4 Polyoxyalkylene triol, which is basically a ring-opening polymer of polypropylene oxide, has a molecular weight of 30,000, a total unsaturation degree of 0.020 meq/g, and contains 10% by weight of oxyethylene groups at the terminals using glycerin as an initiator. D to total unsaturation 0.095 meq/g by the method described in Example 1
A terminal unsaturated group-containing polyoxyalkylene polymer D' was obtained. Furthermore, by the method described in Example 1, a silicon-terminated modified product having a terminal dimethoxysilyl group was obtained. 1 part of dibutyltin dilaurate was added to 100 parts of the silicon-terminated modified product to obtain a -component type room temperature curable composition D''.

Comparative Example: Polyoxypropylene diol E having a molecular weight of 10,000 and a total unsaturation degree of 0.020 meq/g synthesized by ring-opening polymerization of propylene oxide using dipropylene glycol as an initiator was subjected to the method described in Example 1. A terminal unsaturated group-containing polyoxyalkylene polymer E' with a total unsaturation degree of 0.093 meQ/g was obtained, and a terminal silicon modified product having terminal methyldimethoxysilyl groups was obtained from E' according to Example 1. 1 part of dibutyltin dilaurate was added to 100 parts of the silicon modified product to obtain a -component type room temperature curable composition E''.

Table 1 shows the curing time, physical properties, and temperature resistance test results of the one-component room-temperature curable composition described above.

Table: Tack after 24 hours at room temperature ×...Tackiness is noticeably large 0...Tackiness is noticeably small Elongation at break (%): Tensile strength (kg/cm2): 50% modulus (kg/am2): Retention rate (initial physical properties %) After 2 weeks at 280°C and 95% RH: After 1 week at 50°C and 70% RH... Small [Effect of the invention] As described above, it is essentially a polyether chain with a terminal hydrolyzable silicon functional group. It has been revealed that by including an oxyethylene group in the polyether chain of a one-component room-temperature curable composition, curing is significantly faster, and the physical properties and durability are not inferior. Such resins are useful as sealants and the like.

Claims (1)

[Claims] Molecular weight per number of terminal functional groups: 2,000 to 20,000
General formula at the end: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ However, R is a monovalent hydrocarbon group or a halogenated hydrocarbon group X is a hydrolyzable group R' is a divalent organic group a is 0 In a room temperature curable resin having a hydrolyzable silicon functional group represented by an integer of .1 or 2, the main chain is essentially a polyether chain, of which 2 to 40% by weight of oxyethylene groups (-OCH_2CH_2- ) A one-component moisture-curable resin composition.