JPS58162660A - Primer composition - Google Patents

Abstract

PURPOSE:To provide a composition suitable for the bonding of a thermo-setting silicone rubber, and giving high bond durability, by compounding a phenyl group- containing polysiloxane resin with a specific amino group-containing silane, alkoxysilane, and an organotitanium compound, etc. CONSTITUTION:100pts.wt. of an organopolysiloxane resin of formulaI(R<1> is hydrocarbon group, >=5mol% of which is phenyl; R<2> is H or alkyl; a is 0.90- 1.80) is mixed with 20-400pts.wt. of an alkoxysilane of formula II (R<3> is hydrocarbon group; R<4> is alkyl; n is 1 or 2), 2-100pts.wt. of an organotitanium compound, an arbitrary amount of an organic solvent, and 0.5-100pts.wt. of an amino group-containing silane of formula III (R<5> is Q2N-, etc.; Q is H or alkyl; R<6> is alkylene; m is 1 or 2), etc. The rubber elasticity can be imparted to the product by adding 10-500pts.wt. of an organopolysiloxane of formula IV (R<7> is hydrocarbon group, >=0.2mol% of which is vinyl; c is 1.9-2.3) to the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a primer composition, and more particularly, it is suitable for adhering heat-curable silicone rubber to various adherends, such as metal surfaces, and is suitable for use at temperatures exceeding 200°C. The present invention relates to a primer composition that can provide excellent adhesive durability even at high temperatures in various atmospheres such as air, steam, and oil.

In recent years, silicone rubber has become popular due to its excellent heat resistance.
．． Widely used in applications requiring rubber-like elastic bodies at high temperatures. However, when these silicone rubbers are used in high temperature atmospheres, 9% of the base material
They are often used as composites bonded to metals such as iron, aluminum, and stainless steel, and are often exposed to heat-resistant lubricants such as silicone oil and steam. In this case, the silicone rubber deteriorates and peels off at the interface with the base material before it ceases to exhibit rubber-like elasticity, so it is desired to develop a primer that can maintain strong adhesion over a long period of time even under harsh conditions. Ta.

Many primer compositions have been proposed for the purpose of improving adhesion under such harsh conditions. Kaisho 5
2-32767), a composition consisting of silicone raw rubber, a vinyl group-containing silicone oil, a polybasic acid allyl ester, and a metal fatty acid salt (JP-A-52-2653)
No. 5), a composition consisting of acrylooxypropylalkoxysilane and iron fatty acid salt (Japanese Patent Laid-Open No. 55-1605)
0 newsletter). However, these primer compositions were not fully satisfactory because the adhesive strength deteriorated when the adhesive part was exposed to harsh conditions of high temperature for a long period of time.The present inventors aimed to improve the above drawbacks. As a result of extensive research, we discovered that excellent heat resistance can be obtained when a specific phenyl group-containing polysiloxane resin is used as one component of a film-forming composition, and we have already provided a primer composition containing this as a main component. However, subsequent studies have shown that even these compositions have insufficient adhesion to a nickel plate, which has an extremely inert surface, and may not be fully satisfactory depending on the conditions of use. found. On the other hand, the present inventors have discovered that if specific amino group-containing silanes are mixed into the primer composition whose main component is the above-mentioned phenyl group-containing polysiloxane resin, excellent adhesion to nickel plates and other metals can be achieved. Show.

The present inventors have also discovered that a primer composition that can maintain adhesive strength for a long period of time even under the above-mentioned harsh conditions of use can be obtained, leading to the present invention.

This invention is as follows.

(4) Average unit formula R,' SiO4-JL -b(0
R2) b (wherein R1 represents a substituted or unsubstituted monovalent hydrocarbon group, and at least 5 moles of +R' are phenyl groups. R2 is a hydrogen atom type or an alkyl group.

a is in the range of α90 to 180, and b is a value such that the proportion of the hydroxyl group or alkoxy group bonded to the gay element atom in the present compound is 0.01% by weight or more. ) Organopolysiloxane resin 1
00 parts by weight.

It is a hydrogen group, R4 is an alkyl group, and n is 1 or 2. 20 to 400 parts by weight of an alkoxysilane or a partially hydrolyzed product thereof.

(b) Organic titanium compound 2 to 100 parts by weight 0 Organic solvent Arbitrary amount and (g) General formula % formula % (In the formula, R4 is the same as above 111 is a group represented by Q, N- t Q2NcH2c%NH- and a nitrogen-containing group selected from the group represented by Q2N(CH2)2NH(CH2)2NH-, Q is a hydrogen atom and 1
R' is an alkyl group selected from alkyl groups of valence 9
m is 1″! 2) or its partial hydrolyzate
A primer composition comprising 0.5 to 100 parts by weight.

and prisoner average unit formula RAS to 4-@-b (OR2)
1. .

(In the formula, R1 represents a substituted or unsubstituted monovalent hydrocarbon group, and at least 5 moles of s R' are phenyl groups. R2 is a hydrogen atom or an alkyl group.

a is in the range of 0.90 to 1.80, and b is a value such that the proportion of hydroxyl or alkoxy groups bonded to silicon atoms in the present compound is 0.01% by weight or more.

) Organopolysiloxane resin represented by
100 parts by weight.

CB) General formula R15i(OR')4-n is a hydrogen group, e R' is an alkyl group, n is 119 is 2. ) 20 to 400 parts by weight of an alkoxysilane or a partially hydrolyzed product thereof.

B. Organic titanium compound 2-100 parts by weight.

■ Organic solvent Any amount.

■ General formula (R'-R'%5i(OR)4 m [in the formula, R) is the same as above, R5 is a group e represented by Q2N-
A group represented by Q2NCH2CH2NH- and Q
a nitrogen-containing group selected from the group represented by 2N(CHxhNll (CH2)2NH-, Q is a hydrogen atom and a group e selected from a monovalent alkyl group, R' is an alkylene group,
Cloudy is 1 or 2. ) Amino group-containing silane or its partial hydrolyzate 0
．． 5 to 100 parts by weight and (1) Average Unit Formula Edition 8i04 @i- (wherein R7 represents a substituted or unsubstituted monovalent hydrocarbon group, and at least 0.2 mol% of R7 is a vinyl group. C is a number in the range of 1.9 to 23.
500 parts by weight of the primer composition.

The carrier component used in the present invention is a group in which R1 is an alkyl group such as a methyl group, an ethyl group, a propyl group, an octadecyl group, an alkenyl group such as a vinyl group or an allyl group, an aryl group such as a phenyl group, or a group thereof. Represents a substituted or unsubstituted monovalent hydrocarbon group, exemplified by one in which the hydrogen atom of is substituted with a halogen atom, a cyano group, etc., and at least 5 moles of R1 must be a phenyl group directly bonded to a silicon atom. There is. This is because the modulus of the film is high when the amount is less than 5 mol.9. In addition, the heat resistance decreased and a film with sufficient durability could not be obtained.

This is because when an organic titanium compound such as n-butyl titanate represented by component 0 is mixed, gelation occurs and a liquefied primer composition cannot be obtained. Preferably it is in the range of 10 to 70 mol. R2 is a hydrogen atom or an alkyl group exemplified by a methyl group, an ethyl group, a propyl group, a dodecyl group, and the like. a is in the range of 0.90 to R80, and b is a value such that the proportion of the hydroxyl group or alkoxy group bonded to the silicon atom in the present compound is α01% by weight or more.

Such an organopolysiloxane resin having a hydroxyl group or an alkoxy group bonded to a silicon atom is the main component of the composition of the present invention, and its synthesis method is well known.

That is, 1, for example, D O,90~R per silicon atom.
11m each of chlorosilane or alkoxysilane selected to have 80 monovalent hydrocarbon groups or a mixture of two or more.

Obtained by hydrolysis in water or a mixture of water and an organic solvent. In the present invention, not only this hydrolyzed organopolysiloxane resin but also an organopolysiloxane resin obtained by further heat treatment and condensation polymerization can be used. In addition, organopolysiloxane resin 2
It is also possible to use a mixture of more than one species;
Organopolysiloxane resins in which hydroxyl groups and aldoxy groups are mixed in one molecule can also be used. This organopolysiloxane resin can be prepared using various organic solvents 9 such as benzene,
It is preferable to use it in the form of a solution in an aromatic organic solvent such as toluene or xylene.The alkoxysilane or its partial hydrolyzate as component (6) used in the present invention is preferably used in the form of an alkoxysilane or a partially hydrolyzed product thereof, which is used in the present invention and adheres to the benihomono of the present invention. It is a necessary ingredient to impart sex. R3 in the above formula is a vinyl group or an allyl group.

It is a monovalent aliphatic unsaturated bond-containing hydrocarbon group exemplified by methacryloxy group, acryloxy group, etc., and R4 is an alkyl group exemplified by methyl group, ethyl group, n-propyl group, inpropyl group, etc. . Preferred among these alkoxysilanes are trialkoxysilanes represented by the general formula % (%) (wherein d is Ol or 1.R is as described above) (in the formula +R" is a hydrogen atom or methyl group, R6 is an alkylev group exemplified by ethylene group, propylene group, butylene group, etc., and t is as described above.) Such trialkoxysilanes include vinyltrimethoxy Examples include silane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, allyltrimethoxine, allyltriethoxysilane, etc. These trialkoxysilas can also be used as their partially hydrolyzed products.The blending ratio is 1 to 1.
The amount ranges from 20 to 400 parts by weight per 00 parts by weight.

The organic titanium compound (O component) used in the present invention includes an organic titanate ester, a condensation product thereof, or a titanium chelate compound.

This cures the primer composition of the present invention.

It not only provides air-drying properties, but also has the effect of significantly improving heat resistance to 9% adhesion. Such compounds include tetraisopropyl titanate, tetra-n-butyl titanate, butyl titanate dimer,
Tetra(2-ethylhexyl) titanate and polymers thereof, titanium acetylacetenate, polytitanium acetylacetenate, titanium octylglute, teta/lactate.

Titanium chelate compounds such as titanium lactate ethyl ester and butane triethanolaminate can be used in combination or alone. The blending ratio of this component is 2 for 100 parts by weight of component (4).
A range of 100 parts by weight is suitable. This is because if the amount is less than 2 parts by weight, the primer film will be difficult to cure and sufficient adhesive performance will not be obtained, and if it exceeds 100 parts by weight, the storage stability of the composition of the present invention tends to decrease. From this point of view, it is necessary to appropriately select an organic titanium compound in the present invention, and when obtaining a primer composition with good storage stability, a titanium chelate compound typified by diimpropoxytitanium bisacetylacetenate is preferred. used.

Component (2) used in the present invention is an organic solvent for dissolving the composition of the present invention, and this is selected in consideration of solubility and evaporability during application as a primer.

fl eva, ) toluene, xylene, benzene, heptane, hexane, trichlorethylene, perchlorethylene, methylene chloride, ethanol, impropatol, butanol, etc., and these may be used alone or in combination with 2a! It is used as a mixed solvent for the above. This blending ratio is not particularly limited since it is advantageous to dissolve the composition of the present invention and use it as a primer after adjusting the viscosity to be suitable for actual coating work.

Component (2) used in the present invention is a silane that has the effect of adhering the composition of the present invention to substrates that are extremely difficult to adhere to, such as nickel plates.

Group represented by R5a Q2N- in the formula + Q2NCH
A group represented by 2CH2- and Q, N(CH2)2
It is a nitrogen-containing group represented by NH(CH2)2NH.

Q is a hydrogen atom and a group selected from alkyl groups such as methyl, ethyl, and propyl; R6 is an alkylene group such as ethylene, propylene, and butylene, and 9m is 1 or 2; A group-containing silane or a partial hydrolyzate thereof, such as γ-aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane,
Examples include -(2-aminoethyl)aminopropyltrimethoxysilane, di[γ-(2-aminoethyl)aminopropyltrimethoxysilane, and aminoalkylalkoxysilane. These blending amounts are α5 to 10 per 100 parts by weight of the prisoner ingredient.
If it exceeds 100 parts by weight, the film of the primer composition of the present invention becomes too hard, and
．． This is because if the amount is less than 5 parts by weight, the effect of improving adhesion will not be sufficient.

This is intended to impart rubber-like elastic properties to the primer composition of the present invention, which is composed of the [F] acid component to component (2) used in the present invention, and to further improve the intended performance of the primer. 87 expanded methyl group, ethyl group in the formula,
Alkyl groups such as propyl groups and dodecyl groups, cycloalkyl groups such as cyclohexyl groups, alkenyl groups such as vinyl groups and allyl groups, aryl groups such as phenyl groups, and those whose hydrogen atoms are substituted with halogen atoms, cyano groups, etc. represents a substituted or unsubstituted monovalent hydrocarbon group exemplified by: At least 0.2 mole of R7 must be a vinyl group. This means that the amount of vinyl groups is 0.
If the amount is less than 2 molt, sufficient adhesive strength cannot be obtained, and peeling tends to occur between the primer film and the silicone rubber layer. The reason why the viscosity of this organopolysiloxane at 25'0 was set to be 5000 7 cm or more is that if a low viscosity lower than this is used, the primer film will be weakened, so when adhering the silicone rubber by pressure bonding,
This is because the primer composition is washed away, resulting in no adhesion or partial adhesion failure. In this sense, it is preferable that the [F] acid component used in the present invention has a viscosity of 100,000 centistics or more at 4° C. (commonly called gum).

The molecular chain terminals of this organopolysiloxane include silanol group, dimethylvinylsilyl group, methylvinylphenylsilyl group, )+7 methylsilyl group, and dimethylphenylsilyl group.

An example is a methyldiphenylsilyl group, but the group is not limited to a parrot.

[F] The amount of acid component blended is 10 parts by weight per 100 parts by weight of the prisoner component.
~500 parts by weight is used because if it is less than 10 parts by weight, rubber elasticity cannot be imparted, so when the component ψ) is blended, the effect will be slight, and if it exceeds 500 parts by weight, the adhesive strength will decrease. This is because it comes.

The composition of the present invention can be easily obtained by simply uniformly mixing the components of (1) or (2) described above. For further improvement, various inorganic fillers such as finely powdered silica may be added and mixed. In this case, a surface-treated silica filler is suitable as the filler. Furthermore, it is also an object of the present invention to add conventionally known heat resisting agents, 9 colorants, and other additives such as 5 red iron, cerium oxide, cerium hydroxide, cerium fatty acid salts, iron fatty acid salts, titanium oxide, and carbon black. It is considered voluntary as long as it does not compromise the nature of the decision.

When using the composition of the present invention, it is preferable to apply the composition to an adherend and air dry it for 30 minutes or more before adhering the silicone rubber.

In some cases, do not bake to ensure hardening. It's okay to ignore reason.

When using the composition of the present invention as a primer, iron,
Synthesis of various metals such as aluminum, nickel, chromium, zinc, steel, their alloys, acrylic resin, phenolic resin, Epoquin resin, etc.! It is possible to firmly adhere silicone rubber to the surface of IJI resin material, and
Its adhesive strength does not deteriorate even when exposed to high-temperature oil or water vapor, which is an excellent feature. Taking advantage of these features, we can bond silicone rubber to the housing of an oil seal, bond the core bar of a copier roll to silicone rubber, bond the core bar of an engine/mount to silicone rubber, and bond silicone rubber to other metals. It is effectively used as a primer when

Examples are shown below. Examples Middle and Chi mean parts by weight and parts by weight, respectively. Note that e Me represents a methyl group, and φ represents a phenyl group.

Example I 100 parts by weight of a methylphenylsiloxane resin with a hydroxyl group content of 39b, 100 parts by weight of a methylphenylsiloxane resin with a hydroxyl group content of 39b, γ-methacryloxypropyltrimethoxysilane 100 parts by weight, 10 parts of diisopropoxy titanium bis(acetylacetenate), 43 parts of toluene
0 parts and 10 parts of r-(2-aminoethyl)aminoglobil trimethoxycin were mixed to obtain a primer composition as a uniform dispersion.This composition was applied to mild steel plates, aluminum plates, and stainless steel plates. They were coated on a nickel-plated plate, heated and air-dried at room temperature, and used as a crosslinking agent using the 90 method: α5soλ5dimethyl 2. ．． A 4 m thick unvulcanized molded product of silicone rubber Co/Bac/D (SH52U' manufactured by Tone Silicone) to which 5-di(t-butylperoxy)hexane was added was brought into close contact with the primer-coated surface. Made of pressure 30.

When the silicone rubber was cured by heating under pressure for 10 minutes at a temperature of 170° C., a test plate was obtained in which the silicone rubber and the metal plate were firmly adhered.

These test plates were divided into two parts, one of which was immersed in dimethyl silicone oil (viscosity 1100 centistokes at 25°C, 5H200 manufactured by Tone Silicone) kept at a temperature of 200°C, and left for 1, 10, and 20 days. When they were taken out afterwards, no peeling was observed between the metal and silicone rubber.

The other piece was placed in a heating oven kept at a temperature of 230° C., and the samples were left for 1 day, 10 days, and several days. When the samples were taken out, no peeling between the metal and the silicone rubber was observed in any case.

The same test as above was conducted on a prime mer composition obtained in the same manner except that γ-(2-aminoethyl)aminopropyltrimethoxysilane among the components of the above composition was not mixed due to the ratio. However, for the mild steel plate, aluminum plate, and stainless steel tail plate, no peeling was observed between the metal and the silicone rubber, but for the nickel plated plate, the silicone rubber was removed 10 days after being immersed in silicone oil. It was peeling off.

Example 2 &SiO% unit 4 molti, mole iO% unit molti.

Me! It is composed of 1 unit of 19 moles of SiO units, 1 mole of dimethylsiloxane unit whose molecular chain end is blocked with a hydroxyl group, and 3 mole of methylvinylsiloxane unit in 100 parts of methylphenyl polysiloxane resin with a hydroxyl group content of 25%. viscosity 2IOoo,
A mixed solution was prepared by adding 1500 parts of toluene to 100 parts of centistoke polymethylvinylsiloxane gum and stirring well. Next, 100 parts of r-methacryloxypropyltrimethoxysilane and 15 parts of diisopropoxytitanium bisacetylacetenate were added to form a uniform dispersion.

Next, 15 parts of Kr-(2-aminoethyl)aminopropyltrimethoxysilane were added and mixed.

This composition was applied to a mild steel plate, an aluminum plate, a stainless steel plate, and a nickel metal plate, respectively, and left at room temperature for 0 minutes to air dry.

Next, O. S S 2.5 dimethyl 2,5
A 4 m thick unvulcanized molded product of a silicone rubber compound (5H-52U manufactured by Silicone ■) to which di(t-butylperoxy)hexane was added was brought into close contact with the primer-coated surface under a pressure of 30.

When the silicone rubber was cured at a temperature of 170°C, a test plate in which the silicone rubber and the metal plate were firmly bonded was obtained. These test plates were divided into two parts, and one part was heated to 23°C.
Dimethyl silicone oil (viscosity 100 centistokes) maintained at 0°C.

Soaked in Tone Silicone 5H200) for 3 days.

When the samples were taken out after being left for 10 and 20 days, no peeling between the metal and rubber layers was observed. The remaining test plate was left in a heated oven at 230°C for 3 days, then 1
0 days. When the samples were left to stand for 20 days and then taken out, no peeling between the metal plate and the silicone rubber was observed.

For comparison, among the above compositions, γ-(2-aminoethyl)
The same test as above was conducted on a primer composition obtained in the same manner except that aminopropyltrimethoxysilane was not mixed.

Soft SS. For both the aluminum plate and the stainless steel plate, peeling between the metal plate and the silicone rubber was observed. As for the nickel-plated plate, the silicone rubber was peeled off 10 days after being immersed in silicone oil.

Example 3 A primer composition was prepared in the same manner as in Example 1 except that allyltriethoxysilane was used instead of γ-methacryloxypropyltrimethoxysilane in Example 1.

Using this primer composition, an adhesive durability test was conducted under the same conditions as in Example 1, and results similar to those of Example 1 were obtained.

Example 4 A primer composition was prepared in the same manner as in Example 2, except that allyltriethoxysilane was used in place of r-methacryloxypropyltrimethoxysilane in Example 2, and the other conditions were the same as in Example 2.

When an adhesive durability test was conducted using this primer composition under the same conditions as in Example 2, the same results as in Example 2 were obtained.

△

Claims (1)

[Claims] 1 prisoner average unit formula RASiOa -@-b (OR2)
b (in the formula + R'' represents a substituted or unsubstituted monovalent hydrocarbon group, at least 5 moles of R are phenyl groups, R2 is a hydrogen atom or L alkyl group, a is α90 -1.80, and b indicates a value at which the proportion of hydroxyl or alkoxy groups bonded to silicon atoms in the compound is 0.01% by weight or more.)
100 parts by weight of an organopolysiloxane resin represented by: (6) General formula RFI S i (OR')4-Hxiang (in the formula, 13 is a monovalent aliphatic non-alloyed hydrocarbon group, R4 is an alkyl group, and '9゜n is 1 or 2) 20 to 400 parts by weight of an alkoxysilane or a partially hydrolyzed product thereof. 0 Organic titanium compound 2 to 100 parts by weight ■ Organic solvent Arbitrary amount and (2) general formula % formula %) (In the formula, t R' is the same as above, R5 is a group represented by -, Q, NC%C%NH - and Q
sNα':Hs)sNH(CHz)zNitrogen-containing group remaining from the group represented by NH-, Q is a group selected from a hydrogen atom and a monovalent alkyl group + R' is an alkylene group 9
m is 1t7'h is 2. ) Amino group-containing silane or its partial hydrolyzate 0.5-1
1. A primer composition comprising: 0.00 parts by weight. (In the formula, 11 represents a substituted or unsubstituted -valent hydrocarbon group, and at least 5 moles of R1 are phenyl groups. R2 is a hydrogen atom or an alkyl group. a is from 0.90 to 1.80. 100 parts by weight of an organopolysiloxane resin represented by the following formula (100 parts by weight). It is a hydrogenated group and tR is an alkyl group. n is 1 or 2. 20 to 400 parts by weight of an alkoxysilane or a partially hydrolyzed product thereof. 2 to 100 parts by weight of an organic titanium compound. ■ Organic solvent Any amount. (g) General formula (R5R'-)fnSi(OR')4m(
In the formula, R4 is the same as above, t is a group represented by Q2N-, a group represented by QMCHaNH- and QzN(C
Hz)2NH(CH2)2NH-te; Q is a group selected from a hydrogen atom and a monovalent alkyl group; R6 is an alkylene group; 1m is 1 or 2; ) and 0.5 to 100 parts by weight of an amino group-containing silane or its partial hydrolyzate represented by Organopolysiloxane 10 having a viscosity at 5° C. of 5 ooo centistrist 1x or more, represented by the formula tR', at least 0.2 mole of which is a vinyl group.The number ranges from caL9 to 2.3. 500 parts by weight of a primer composition.