JPS61225250A - Room temperature curing organosiloxane composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which is free from formation of creeping or blobbing on the surfaces of joints and is useful as a building sealant, consisting of an organopolysiloxane compsn. and at least one org. compd. selected from among org. carboxylic acids and org. acid anhydrides. CONSTITUTION:0.01-5pts. (by weight; the same applies hereinbelow) at least one org. compd. selected from org. carboxylic acids and org. acid anhydrides is mixed with 100pts.wt. organopolysiloxane compsn. consisting of 100pts. diorganosiloxane (a) which has a viscosity of 100-1,000,000 and a linear structure, both terminals of which are blocked by OH group and which is represented by formula I [wherein R<1> is alkyl, alkenyl, aryl, (substd.) monovalent hydrocarbon group; p is a positive integer], 0.1-25pts. organosilicon compd. (b) contg. at least two hydrolyzable groups of formula II (wherein R<2> is R<1>; Y is ketoxime, alkoxy, amide, etc.; 0<=b<4; 0<c<=4, 1.7<b+c<=4) attached to Si atom, 1-400pts. filler (c) such as precipitated silica and 0-5pts. curing catalyst (d) such as a guanidyl group-contg. silane.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a room-temperature curable organopolysiloxane composition, *
It hardens at room temperature under the action of moisture in nitrogen. The present invention relates to a room-temperature-curable organopolysiloxane composition that is useful as an architectural sealant that does not cause concave joint surfaces during joint construction.

(Prior Art) Conventionally, materials cure at room temperature to become rubber-like elastic bodies. So-called room temperature organopolysiloxane composition (hereinafter referred to as "RTv")
Regarding "composition" for short, there are known compositions having various compositions. Regardless of the type, these RTV compositions can be used in a wide variety of applications because the rubber-like elastomer that is superior to them has superior weather resistance, durability, heat resistance, cold resistance, etc. compared to other organic rubbers. It is widely used in the field of construction, especially in the construction field, where it is often used for bonding glass to glass, metal to glass, sealing concrete joints, etc. Among these, rubber-like elastic materials with low modulus and high elongation are used. There is an increasing demand for silicone sealants, which are used to seal joints between large construction members where there is a lot of movement.

However, the two-component low-sodulus, high-elongation type R'I''/composition that is used as a silicone sealant has what is known in the industry as 1 apata' on the joint surface after it hardens. The disadvantage is that a concave portion is formed, which impairs the aesthetic appearance.

This one avatar' phenomenon is a two-component R
Air is incorporated during kneading of the Tv composition.

It is thought that this air escapes during curing after construction, and defoaming operations are carried out during this cross-connection, but it is difficult to do this completely.

There is a need to ensure that this effective countermeasure is taken.

(Structure of the Invention) The present invention #4 is a product of RTV@ that solves these disadvantages, and is made of 7100 parts by weight of diorganopolysiloxa whose molecular chain terminals are blocked with hydroxyl groups. , 2] 0.1 to 25 parts by weight of an organosilicon compound having at least two hydrolyzable groups bonded to a molecularly neutralized silicon atom;
3) 100 parts by weight of an organopolysiloxane composition consisting of 1 to 400 parts by weight of a filler, 4) 0 to 5 parts by weight of a curing catalyst, and 5) one type or 2N selected from organic carboxylic acids and organic acid anhydrides. It is characterized by adding 0.01 to 5 parts by weight of the above organic compounds.

That is, as a result of various studies on R'I'V compositions that do not cause pressure generation on the joint surface even when a joint is constructed, the present inventors found that the known R'I'V composition consisting of the above-mentioned components 1] to 4] When an organic carboxylic acid or anhydrous organic acid is added to the composition as component 5), the occurrence of ``avatar'' phenomenon in the joint after curing when this composition is applied to the joint.
They discovered that it is possible to prevent this, and completed the present invention by conducting research on the type and amount of this organic compound to be added.

The R'I'VM composition of the present invention is composed of paraboloids described above.
) The organosiloxane composition consisting of the components may be any known organosiloxane composition. Therefore, the diorganopolysiloxane as the above-mentioned component 1) which is the main component of the composition of the present invention may be a diorganopolysiloxane which has both molecular chain ends blocked with hydroxyl groups and is conventionally known as a raw material for silicone rubber. R1 is an alkyl group such as a methyl group, an ethyl group, a propyl group, or a vinyl group.

From alkenyl groups such as allyl groups, phenyl groups rx tonoaryl groups, cycloalkyl groups such as cyclohexyl groups, or groups in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with herogen atoms, cyano groups, etc. The unsubstituted or substituted monovalent hydrocarbon groups selected from the same or different species, p being a positive integer, have a viscosity of 100c8 or less, resulting in a cured elastic body with excellent physical strength. If the viscosity is 1,000,000c8 or more, the viscosity of the composition of the present invention will be too high and the workability during use will be poor. It is said to belong to Further, this diorganopolysiloxane has a substantially ff1K linear structure.

A siloxane having a three-dimensional structure may be introduced in a small amount.

Next, component 2) constituting the composition of the present invention is considered to be an essential component for curing the composition of the present invention at room temperature and pressure in the presence of moisture. It is an organosilicon compound having at least two hydrolyzable groups.

This hydrolyzable group includes the same or different unsubstituted or substituted monovalent hydrocarbon group as in the formula % R1, Y is a ketoxime group, an alkoxy group, an acyloxy group, an alkenyloxy group, an abano group, a? Same or different groups selected from nooxy group, amide group, etc., b, 0 is 0≦b〈4゜C is 0〈0≦4.1.7〉
b+o≦4.

It is also represented by R81Z, where R is the same as the preceding R2, and 2 is a ketoxime group or an alkoxy group.

Examples include a group selected from an acyloxy group and an alkenyloxy group, and a silane or a partial hydrolyzate thereof in which e is 0 or 1. Silane or organosiloxane may be used.

In addition, this organosilicon compound must have two or more hydrolyzable groups as described above in order to cure the RTV composition in the presence of moisture.
In order to obtain an elastic body with low stiffness and high elongation by chemical reaction, it is better to use an organosilicon compound having two hydrolyzable groups. It is recommended that the

Examples of the organic silicon compound include alkoxysilanes such as methyltrimethoxysilane, vinyltriethoxysilane, 3-chloropropyltrimethoxysilane, and 3-aminopropyltriethoxysilane, and methyltris(dimethyloxime)silane.

Ketoxime silanes such as methyltris(methylethylketoxime)silane, tetra[methylethylketoximefusilane], acyloxysilanes such as vinyltriacetoxysilane, methyltriacetoxysilane, alkenyloxysilanes such as vinyltripropenyloxysilane, methyltriisobutenyloxysilane , phenyltris(N-methylacetamidobunrane, vinyltris(N-ethylacedoadocosilane, etc.), vinyltris(N-butylamino)silane, phenyltris(N,N-diethylamino)silane, etc. A i
Nosilane, methyltris (N.

N-dimethylaminooxy)silane, vinyltris(N
, N-diethylaminooxy) silane, and partial hydrolysates of one or more thereof.

The amount used is 0.000 parts per 100 parts by weight of component 1 above.
If it is less than 5 parts by weight, the curing of the composition of the present invention will not proceed well, and if it exceeds 25 parts by weight, the physical properties of the cured elastic body obtained will deteriorate and it will be economically disadvantageous.
The range is in parts by weight.

In addition, the filler as the component 3) constituting the composition of the present invention may be a known filler, and K is humid silica, precipitated silica, quartz powder, soybean earth, titanium oxide, aluminum oxide, lead oxide, iron oxide, carbon black, bentonite, graphite, calcium carbonate, mica,
Examples include clay, glass beads, glass microballoons, glass balloons, glass fibers, polyvinyl chloride beads, polystyrene beads, acrylic beads, etc.
This may be fumed silica whose surface has been treated with a silane-siloxane such as hexamethyldisilazane, dimethyldichlorosilane, or octamethylcyclotetrasiloxane. In addition, the usage amount of this 3) component is as described above.
If the amount is less than 1 part by weight per 100 parts by weight of the components, the cured elastic body obtained from the composition of the present invention will have poor mechanical strength.

If it exceeds 400 parts by weight, a good quality rubber elastic body cannot be obtained, so the range is from 1 to 400 parts by weight, preferably from 50 to 1.
The amount is preferably in the range of 50 parts by weight.

As the curing catalyst as component 4) constituting the composition of the present invention, various catalysts that have been conventionally used in this type of composition can be used, and K is lead-2-
Ethyl octoate, diptyltin diacetate, diptyltin silacrate, phthyltin tri-2-ethylhexoate.

Iron-2-ethylhexoate, cobalt-2-ethylhexoate, manganese-2-ethylhexoate, zinc-2-ethylhexoate, sootous caprylate, tin naphthenate, tin oleate.

Metallic lead I tetracupyl titanate, tetra-2- of organic carboxylic acids such as tin butyrate, titanium naphthenate, zinc naphthenate, cobalt naphthenate, zinc stearate, etc.
Ethylhexyl titanate.

Organic titanate esters such as triethanolamine titanate and tetra(isopropenyloxy) titanate;
Organic titanium compounds such as organosiloxytitanium and β-carbonyl titanium Alkoxyaluminum compounds #
Aminoalkyl group-substituted alkoxysilanes such as 3-aminopropyltriethoxysilane, N-()rimethoxysilyl]ethylenediamine, and hexylaine. Amine compounds such as dodecylamine phosphate and their salts 8
Quaternary salts such as benzyltriethylammonium acetate
lower fatty acids of alkali metals such as potassium acetate, sodium acetate, lithium oxalate, etc. - dialkylhydroxylamines such as dimethylhydroxyamine, diethylhydroxylamine, etc. Guanidine compounds and guanidyl groups represented by the linear formula % formula % Examples include containing silane or siloxane.

This is not limited to one type, but may be used as a mixture of two or more types. This curing catalyst is
) Depending on the type of hydrolyzable group bonded to the silicon atom in the component, it may not be used at all, but 1) Usually, if it is too small relative to 100 parts by weight of the above-mentioned 1) component, it may be difficult to cure the composition. In addition to requiring a long time, if the molded product is thick, it will be difficult to harden it uniformly deep down.
If the amount is too high, the curing time will be too short, causing inconvenience on the work surface, and the resulting cured product will have poor heat resistance and weather resistance, so the range is from 0.01 to 5 parts by weight.

Preferably it is in the range of 0.1 to 3 times.

The composition of the present invention is an organic compound composed of organopolysiloxane containing the above-mentioned components 1 to 4 for solving the Avatar I phenomenon that often occurs when this composition is used as a sealant. However, this organic compound must be an organic carboxylic acid or an organic acid anhydride.

The organic compound as this 5) component has the general formula R-0
00H.

(R is a monovalent hydrocarbon group, R is a divalent hydrocarbon group 1m-1 to 20) or the anhydrides of these organic acids. may be one type or a mixture of two or more types, and examples include Chomi.

OH0OOH, OH0OOH.

3 2 Attack OH0OOH
,OHCoon.

3-cho 4I O□-,,0OOH.

C1(,-0H-COOH,Oli,-0)1-Coo
n.

○=0-0゜0H3(OB,)4000H,0R1(OH,),00
011゜ah, (on2), 000B, @OH
s (OJ)s OOCIH (capric acid).

OH, (O)l, )0,0OOH (stearic acid).

0H3 (011,), 0OOH (myristic acid).

0H3(OHs)40H=OHO1!20H=OB(O
H, ), aooH (linoleic acid).

OH, (Oii*) 10000H (lauric acid).

N.H.

OH3 (OH (OH) OOOH) (Tarashi a).

meaning OH,=OHOOOH (acrylic #2).

0LOH20H,0OOH (β-chlorobutetepionic acid)
.

a, Hl Summer 0'Hs (CH2) ORC100H (2-ethylhexanoic acid).

CRs (OH2), CH=CH(OH,), 0OOH
(oleic acid) - OH.

! OH,=OOOOOH (methacrylic acid).

0R2=OH(O)1. ), 0OOHC')
il).

OH, -00011! cHs -COOH (cohelic acid).

OH-0 OR, -0 11 anhydrous dicarbonate #).

The amount of this organic compound to be added is 0.01 part by weight or less per 100 parts by weight of the xane composition, since the organoboric acid consisting of components 1) to 4 above cannot solve the 1 apata phenomenon during curing of this composition. If the amount is not sufficient and the amount exceeds 5 parts by weight, it will be economically disadvantageous and there is a possibility that the action of the acid in the composition will adversely affect the physical properties of the cured product.

It is necessary to range from 0.01 to 5 parts by weight, and the preferred range is from 0.01 to 3 parts by weight.

The composition of the present invention can be obtained by mixing the components 1) to 5), which have been prepared above, and this mixing may be carried out by a conventionally known mixing means. Even if you add ingredients 1) to 5) after mixing them uniformly,
The components may be homogeneously mixed at the same time. However, in the composition of the present invention, the main component and the curing agent are usually packaged separately, and the two are mixed immediately before use. This is because it is provided as a so-called liquid sealant.

It is preferable to separately mix components 3) and 4) and components 3) and 5) to form a 5311 package.

1. A plasticizer may be added to the composition of the present invention if necessary.

Contains coloring agents such as pigments, twist-resistance imparting agents, chinchrotropy agents - antibacterial and anti-piping agents, amino groups, epoxy groups, thiol groups, etc. There is no problem in adding and blending a predetermined amount of an adhesion improver such as so-called carbon functional silane as long as it does not impede the object of the present invention.

Next, examples of the present invention and comparative examples will be given.

All "parts" in each example indicate "parts by weight", and the viscosity indicates a value measured at 25°C.

Both ends of the Example molecule were capped with hydroxyl groups. Viscosity is s, ooo
A base compound is made by adding 40 parts of calcium carbonate to 60 parts of dimethylpolysiloxane of CS, and to 100 parts of this base compound, the types shown in Table 1, t
A sealant composition is obtained by mixing the organic compound represented by the following formula with 25 parts of a siloxane mixture consisting of 95% xane and 5% siloxane represented by the following formula, and defoaming under reduced pressure at 750 mHg for 25 minutes. made.

Next, this composition was filled into a virtual joint measuring 20 x 20 x 200 mm, and after 124 hours, the surface condition of the hardened joint was observed, and the results shown in Table 1 were obtained.

Claims (1)

[Claims] 1.1) Diorganopolysiloxane whose molecular chain ends are capped with hydroxyl groups 100 parts by weight 2) Organosilicon having at least two hydrolyzable groups bonded to silicon atoms in the molecule Elementary compound 0.1-25
parts by weight 3) filler 1 to 400 parts by weight 4) curing catalyst 0 to 5 parts by weight per 100 parts by weight of the organopolysiloxane composition 5) one or two selected from organic carboxylic acids and organic acid anhydrides A room-temperature-curable organopolysiloxane composition, characterized in that it contains 0.01 to 5 parts by weight of one or more organic compounds.