JPH07310051A - Surface treatment agent for rubber articles - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide an aqueous silicone-based surface treatment agent which forms a film having excellent adhesion, abrasion resistance and surface smoothness on the surface of a rubber article. [Constitution] A surface treatment agent for a rubber article, which is prepared by mixing the following components 1) to 5). 1) Aqueous dispersion of non-fluidic branched silicone, 2) Aqueous emulsion of hydrolysis-condensation product of dialkoxysilane having epoxy group-containing organic group, 3) Hydrolysis of dialkoxysilane having aminoalkyl group Aqueous dispersion of decomposition-condensation product, 4) trialkoxysilane having a (meth) acrylic group-containing organic group or trialkoxysilane having an aminoalkyl group, 5) aqueous dispersion of silicone rubber particles.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a surface treating agent for rubber articles. The rubber article treated with the surface treatment agent of the present invention is suitable for applications in which it is repeatedly rubbed.

[0002]

2. Description of the Related Art Conventionally, a method of surface-treating with a silicone resin composition has been proposed in order to impart abrasion resistance to the surface of various rubber materials. For example, a method of surface-treating with a composition consisting of an epoxy group-containing polyorganosiloxane and an amino group-containing silane and / or siloxane (Japanese Patent Publication No. 60-58).
-50226), and a method of surface-treating with a composition containing a polyorganosiloxane having a hydroxyl group and a diorganohydrogensiloxane (see JP-B-54-43023 and JP-B-56-47864). .

[0003]

However, it cannot be said that the adhesiveness to the substrate, the abrasion resistance, and the surface smoothness are sufficient, and since it is a solvent-diluting type treatment agent, it has an adverse effect on the environment and There is a problem in terms of safety. The present invention has been made in order to provide a surface treating agent for a rubber article using a silicone composition, in which the above problems are improved.

[0004]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that the following processing agents can achieve the object. That is, the present invention relates to a surface treatment agent for rubber articles, which comprises: 1) a general formula R ¹ ₂ SiO _2/2 and R ¹ SiO _3/2 as the first component (where R ¹ is An aqueous dispersion of a non-fluidic branched silicone having 1 to 20 carbon atoms (unsubstituted or substituted monovalent hydrocarbon group) as a constitutional unit, 2) the general formula R ² SiR ³ (OR ⁴ ) ₂ (here R ²
Is an epoxy group-containing monovalent organic group having 5 to 20 carbon atoms, R
³ , R ⁴ is an aqueous emulsion of a hydrolysis-condensation product of a dialkoxysilane represented by an unsubstituted or substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, 3) the general formula R ⁵ as the third component R ⁶ N (CH ₂ ) _a [NR ⁷ (CH ₂ ) _b ] _c
SiR ⁸ (OR ⁹ ) ₂ (wherein R ⁵ , R ⁶ , and R ⁷ are each a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, and R ⁸ and R ⁹ are each 1 carbon atoms. To 6 unsubstituted or substituted monovalent hydrocarbon groups, a, b and c are 1 ≦ a ≦ 6 and 1 ≦ b ≦
6, 0 ≦ c ≦ 3) Aqueous dispersion of hydrolysis-condensation product of dialkoxysilane, 4) General formula R ¹⁰ Si (OR ¹¹ ) ₃ (where R ¹⁰
Is a (meth) acrylic group-containing monovalent organic group having 5 to 20 carbon atoms, and R ¹¹ is a trialkoxysilane represented by an unsubstituted or substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, or a general formula
R ¹² R ¹³ N (CH ₂ ) _d [NR ¹⁴ (CH ₂ ) _e ] _f Si (OR ¹⁵ ) ₃ (where R ¹² ,
R ¹³ and R ¹⁴ are each hydrogen or a group selected from a monovalent hydrocarbon group having 1 to 6 carbon atoms and a halogenated hydrocarbon group;
¹⁵ is a group selected from a monovalent hydrocarbon group having 1 to 6 carbon atoms and a halogenated hydrocarbon group, and 1≤d≤6, 1≤e
≦ 6, 0 ≦ f ≦ 3) trialkoxy silane, 5) an aqueous dispersion of silicone rubber granules as a fifth component, an organopolysiloxane aqueous emulsion is there. The present invention will be described in detail below.

The first component constituting this organopolysiloxane aqueous emulsion is a unit represented by the general formula (1) R ¹ ₂ SiO _2/2 (1) and the general formula (2) R ¹ SiO _3/2 ... An aqueous emulsion of a non-fluidic branched silicone having a unit represented by (2) as a constitutional unit. R ¹ is a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a dodecyl group,
Alkyl group such as tetradecyl group, hexadecyl group, octadecyl group; alkenyl group such as vinyl group, allyl group; aryl group such as phenyl group, tolyl group; cycloalkyl group such as cyclohexyl group; or bond to carbon atom of these groups Illustrative are monovalent hydrocarbon groups in which some or all of the hydrogen atoms are substituted with halogen atoms or organic groups containing epoxy groups, carboxyl groups, amino groups and the like.

Such non-flowable branched silicone aqueous emulsions can be prepared by emulsion polymerization. As the silicone raw material of the siloxane unit represented by the general formula (1), cyclopolysiloxane represented by [R ¹ ₂ SiO] _g (g = 3 to 7), or the formula R ¹⁶ O- [R ¹ ₂ SiO] _{h ^{-R 16, HO- [R 1 2}} SiO] h
-H (wherein R ¹ is the same as described above, R ¹⁶ is an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group and a hexyl group; a cycloalkyl group such as a cyclopentyl group and a cyclohexyl group; a phenyl group; A monovalent hydrocarbon group having 1 to 6 carbon atoms or a halogenated hydrocarbon group such as a halogenoalkyl group such as a fluoropropyl group, particularly a methyl group or an ethyl group is preferable, and h is 1 to 1,000) The diorganopolysiloxane represented by the formula (1) is exemplified, and the silicone raw material of the siloxane unit represented by the general formula (2) is represented by R ¹ Si (OR ¹⁶ ) ₃ (R ¹ and R ¹⁶ are the same as the above). Examples include alkoxysilanes, which can be easily obtained by emulsifying and dispersing them in water with an emulsifier, adding a catalyst to the mixture to cause a polymerization reaction, and deactivating the catalyst after polymerization. But it can.

The emulsifier used in this emulsion polymerization is not particularly limited, and examples thereof include cationic emulsifiers such as quaternary ammonium salts and alkylamine salts; zwitterionic emulsifiers such as alkyl betaines; polyoxyethylene alkyl. Nonionic emulsifiers such as ethers, polyoxyethylene alkyl phenyl ethers, sorbitan fatty acid esters, glycerin fatty acid esters, etc .; acidic anionic emulsifiers such as organic sulfonic acids, alkyl sulfates, etc. One kind or two or more kinds can be used.

When a cationic emulsifier, a zwitterionic emulsifier, or a nonionic emulsifier is used as the catalyst, potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium methylate, ammonia, tetrahydrochloride is used. Examples thereof include alkali compounds such as methylammonium hydroxide, triethylamine, and triethanolamine, but acidic anionic emulsifiers such as organic sulfonic acid and alkyl sulfate have a catalytic action as they are. In addition, in the case of alkaline compounds, inactivation of this catalyst,
Examples thereof include a method of neutralizing with an acid such as acetic acid, phosphoric acid, hydrochloric acid or citric acid. When an acidic anionic emulsifier is used as a catalyst, it is neutralized with an alkaline compound such as potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium methylate, ammonia, tetramethylammonium hydroxide, triethylamine, triethanolamine. There is a method of doing.

If the concentration of the active ingredient in the aqueous emulsion produced in this way is less than 1% by weight, it is uneconomical because the amount of the active ingredient to be blended must be increased, and 70% by weight is required. If it is larger than this, the viscosity of the first component becomes high and handling becomes difficult. Therefore, the range is 1 to 70% by weight, but the preferable range is 10 to 60% by weight.

The second component constituting the organopolysiloxane aqueous emulsion is an epoxy group-containing dialkoxy represented by the general formula (3) R ² SiR ³ (OR ⁴ ) ₂ (3) It is an aqueous emulsion of the hydrolyzed condensate of silane. This R ² is β-glycidoxyethyl, γ-glycidoxypropyl, β- (3,
4-epoxycyclohexyl) ethyl, γ- (3,4-
Epoxycyclohexyl) propyl and the like monovalent organic groups having 5 to 20 carbon atoms, R ³ and R ⁴ are alkyl groups such as methyl group, ethyl group, propyl group, butyl group and hexyl group; cyclopentyl group, cyclohexyl A cycloalkyl group such as a group; a phenyl group; an unsubstituted or substituted monovalent hydrocarbon group having 1 to 6 carbon atoms exemplified by a halogenoalkyl group such as a trifluoropropyl group, and particularly a methyl group or an ethyl group. Preferably there is.

As the epoxy group-containing dialkoxysilane, β-glycidoxyethylmethyldimethoxysilane, β-glycidoxyethylmethyldiethoxysilane,
γ-glycidoxypropylmethyldimethoxysilane, γ
-Glycidoxypropylmethyldiethoxysilane, γ-
Typical examples are (3,4-epoxycyclohexyl) propylmethyldimethoxysilane and γ- (3,4-epoxycyclohexyl) propylmethyldiethoxysilane, but their hydrolysis is acidic to these silanes. It may be carried out by a known method of adding an aqueous solution. According to this method, the dealcoholization condensation reaction easily proceeds, and then the acid is neutralized and the produced alcohol may be distilled off.

The resulting hydrolyzed condensate can be made into an aqueous emulsion by emulsifying and dispersing it in water using a surfactant. There are no particular restrictions on the surfactant used for this emulsification, but this includes polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether,
It is preferable to use a nonionic surfactant such as sorbitan fatty acid ester and glycerin fatty acid ester, and one or more of these may be used. The concentration of the active ingredient in this aqueous emulsion was 1% by weight.
If less than 70% by weight, it is uneconomical because the amount of compounding must be increased, and if it exceeds 70% by weight, the viscosity of this second component becomes high and handling becomes difficult. The amount may be in the range of 1 to 70% by weight, but the preferable range is 10 to 50% by weight.

The third component constituting this organopolysiloxane aqueous emulsion is represented by the general formula (4) R ⁵ R ⁶ N (CH ₂ ) _a [NR ⁷ (CH ₂ ) _b ] _c SiR ⁸ (OR ⁹ ) ₂ ... An aqueous dispersion of a hydrolysis-condensation product of an aminoalkyl group-containing dialkoxysilane represented by (4). This R ⁵ , R
⁶ and R ⁷ are each a hydrogen atom or an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group or a hexyl group; a cycloalkyl group such as a cyclopentyl group or a cyclohexyl group;
Phenyl group: an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, selected from halogenoalkyl groups such as trifluoropropyl group, but having 90 hydrogen atoms.
It is preferably at least mol% and at most 10 mol% of hydrocarbon groups.
R ⁸ and R ⁹ have the same carbon number of 1 to ⁵ as those of R ⁵ , R ⁶ and R ⁷ .
6 is an unsubstituted or halogen-substituted monovalent hydrocarbon group, and particularly preferably a methyl group or an ethyl group.
Of these a, b, and c, when a and b are 0, the desired hydrolyzed condensate cannot be obtained because the Si—N bond is hydrolyzed, and when a is greater than 6, the third component has a characteristic effect. Since the effect of improving the adhesiveness of the rubber surface of 1 is reduced, 1 ≦ a ≦ 6, 1 ≦ b
≦ 6, preferably a and b are 2 or 3,
When c is larger than 3, it is difficult to synthesize it industrially, and therefore 0 ≦ c ≦ 3.

Examples of the aminoalkyl group-containing dialkoxysilane include γ- (N-β-aminoethyl) aminopropylmethyldimethoxysilane, γ- (N-β-aminoethyl) aminopropylmethyldiethoxysilane, and γ.
Typical examples include -aminopropylmethyldimethoxysilane and γ-aminopropylmethyldiethoxysilane. The hydrolysis of these silanes may be carried out according to a known method. Since the dealcoholization condensation reaction of these silanes easily proceeds when water is added to these silanes, the produced alcohol may be distilled off thereafter. When this dialkoxysilane hydrolyzate is mixed with water, it is easily dissolved or dispersed in water to form a uniform aqueous dispersion. The amount of dialkoxysilane in the aqueous dispersion of the third component is 1%. If it is less than 50% by weight, the adhesion of the cured film to the rubber article surface will be low, resulting in poor abrasion resistance, and if it is more than 50% by weight, the viscosity of the liquid will be high and it will be dispersed evenly when blended with other components. Since it is difficult to control the content, it is preferable to set it in the range of 1 to 50% by weight, but this preferable range is set to 10 to 30% by weight. In addition, in order to improve the uniformity of the aqueous dispersion of the third component, formic acid,
A preferred method is to add an organic acid such as acetic acid, propionic acid, malonic acid, maleic acid, and salicylic acid, or an inorganic acid such as hydrochloric acid, phosphoric acid, and sulfuric acid.

The fourth component constituting this organopolysiloxane aqueous emulsion is a (meth) acryl group-containing trivalent compound represented by the general formula (5) R ¹⁰ Si (OR ¹¹ ) _3. Alkoxysilane or an aminoalkyl group represented by the general formula (6) R ¹² R ¹³ N (CH ₂ ) _d [NR ¹⁴ (CH ₂ ) _e ] _f Si (OR ¹⁵ ) ₃ (6) It is a trialkoxysilane.

R ^{10 in the} general formula (5) is a monovalent organic group having 5 to 20 carbon atoms, such as β-acryloxyethyl, γ-acryloxypropyl, β-methacryloxyethyl, γ-methacryloxypropyl. Group, R ¹¹ is exemplified by an alkyl group such as methyl group, ethyl group, propyl group, butyl group and hexyl group; cycloalkyl group such as cyclopentyl group, cyclohexyl group; phenyl group; halogenoalkyl group such as trifluoropropyl group It is preferably an unsubstituted or substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, and particularly preferably a methyl group or an ethyl group. Examples of the (meth) acrylic group-containing trialkoxysilane include β-acryloxyethyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, β-methacryloxyethyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ. -Methacryloxypropyltriethoxysilane and the like are exemplified as typical ones.

R ¹² , R ¹³ and R ^{14 in the} general formula (6) are each a hydrogen atom or an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group or a hexyl group; a cycloalkyl group such as a cyclopentyl group or a cyclohexyl group. Group; phenyl group; unsubstituted or halogen-substituted 1 to 6 carbon atoms selected from halogenoalkyl groups such as trifluoropropyl group
Although it is a valent hydrocarbon group, it is preferably 90 mol% or more of hydrogen atoms and 10 mol% or less of hydrocarbon groups. R ¹⁵ is this R ¹² ,
It is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 6 carbon atoms similar to R ¹³ and R ^14, and particularly preferably a methyl group or an ethyl group. For d, e and f,
When d and e are 0, it is difficult to synthesize industrially, and when it is larger than 6, the effect of improving the adhesiveness of the rubber surface as the characteristic effect of the third component decreases, so 1 ≦ d ≦ 6, 1 ≦ e ≦ 6,
Preferably, d and e are 2 or 3, and f is 3
The larger one is industrially difficult to synthesize, so 0
≦ f ≦ 3. Examples of the aminoalkyl group-containing trialkoxysilane include γ- (N-β-aminoethyl) aminopropyltrimethoxysilane and γ-
(N-β-aminoethyl) aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-
Aminopropyltriethoxysilane and the like are typical examples.

Further, the fifth component constituting the organopolysiloxane aqueous emulsion is an aqueous dispersion of silicone rubber particles, and the silicone rubber particles have a slidability of less than 0.1 μm. And the wear resistance deteriorates when the average particle size is larger than 100 μm, the average particle size is in the range of 0.1 to 100 μm, preferably 1 to 20
μm. The silicone granules may be emulsified and dispersed in water using a surfactant to form an aqueous dispersion of the silicone granules. In particular, a curable silicone is dispersed in water using a surfactant and then cured. It is preferable to use an aqueous dispersion of silicone granules. The curable silicone may be cured by addition reaction, condensation reaction, UV curing, or the like. If the curable silicone is a solid product having rubber elasticity when cured, The organic group bonded to the elementary atom, the molecular structure, the molecular weight and the like are arbitrary.

When this curing is carried out by an addition reaction, it is an organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in one molecule and 1
A method in which an organohydrogenpolysiloxane having at least two hydrogen atoms bonded to silicon atoms in the molecule is emulsified and dispersed in water using a surfactant, and then subjected to an addition reaction using a platinum catalyst. And it is sufficient. The alkenyl group-containing organopolysiloxane may have the alkenyl group at any position in the molecule, but it is particularly preferable that the alkenyl group is at the terminal of the molecule. Examples of the organic group bonded to a silicon atom other than the alkenyl group include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, and a dodecyl group, an aryl group such as a phenyl group, β Examples include aralkyl groups such as -phenylethyl group and β-phenylpropyl group, chloromethyl groups, monovalent substituted hydrocarbon groups such as 3,3,3-trifluoropropyl group, etc. From the viewpoint of maintaining good physical properties, it is preferable that 90 mol% or more of the organic groups bonded to silicon atoms are methyl groups.

The molecular structure of the product may be linear, branched, or a mixture thereof. The molecular weight of this component is not particularly limited. It is difficult to cure if the viscosity at 25 ° C is less than 1 cS, and if it is higher than 10,000 cS, the surface smoothness decreases, so this is in the range of 1 to 10,000 cS. , Preferably 5 to 1,000c
It is preferable to use S, but as a specific example of this organopolysiloxane, the following formula,

[Chemical 1] (Where i and j are 0, 1, 2 or 3 and i + j = 3, k
Is a positive integer, L is 0 or a positive integer and i + L ≧ 2),

[Chemical 2] (Where m is an integer of 2 or more, n is 0 or a positive integer, m
+ N = 4-8),

[Chemical 3] (Where p is 1, 2 or 3, q is 0, 1 or 2 and p
+ Q = 3, r, s, and t are positive integers).

In the organohydrogenpolysiloxane used here, the hydrogen atom bonded to the silicon atom undergoes an addition reaction with the alkenyl group in the siloxane described above by the action of the platinum catalyst to give this composition. The organic group bonded to a silicon atom other than a hydrogen atom is the same as that of the above-mentioned alkenyl group-containing organopolysiloxane, but it is also necessary to maintain good easiness of synthesis and good physical properties. It is preferably a methyl group. The molecular structure of this organohydrogenpolysiloxane is not particularly limited, and it may be linear, branched or cyclic, or a mixture thereof, and the molecular weight is also not particularly limited. In order to improve the compatibility with the above-mentioned alkenyl group-containing organopolysiloxane, it is preferable that the viscosity at 25 ° C. is 1 to 10,000 cS. More preferably, it is 5 to 1,000 cS. In addition, the amount of this component added is the above-mentioned alkenyl group 1
0.5 hydrogen atom bonded to the silicon atom of this component
If the amount is less than 0.5, it is difficult to obtain good curability, and if the amount exceeds 20 hydrogen atoms, the physical properties of the rubber after curing deteriorate, so 0.5-20 The amount is preferably 0.8 to 5 pieces.

The organohydrogenpolysiloxane has the following formula:

[Chemical 4] (Where u is 0 or 1 and v is 2 or 3 and u + v =
3, w is 0 or a positive integer, x is a positive integer, and u + x ≧ 2
Is),

[Chemical 5] (Where y is an integer of 2 or more, z is 0 or a positive integer, and y
+ Z = 4-8),

[Chemical 6] (Where a'is 1, 2 or 3, b'is 0, 1 or 2
And a '+ b' = 3, c ', d'and e'are positive integers).

Further, examples of the platinum-based catalyst used here include platinum-supported carbon or silica, chloroplatinic acid, platinum-olefin complex, platinum-alcohol complex, platinum-phosphorus complex and platinum coordination compound. When the amount of this component used is less than 1 ppm of platinum atom relative to siloxane, curing slows down and is easily affected by catalyst poisons.
Even if it exceeds pm, the improvement of the curing rate cannot be expected and it is not economically preferable. Therefore, the range of 1 to 100 ppm is preferable. In addition, as the surfactant used here, nonionic surfactants such as polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene sorbitan fatty acid ester and glycerin fatty acid ester, which have little adverse effect on the curing reaction, are used. It is preferable to use an agent, and one or more of these may be used.

If the concentration of the active ingredient in the dispersion liquid as the fifth component is less than 1% by weight, it becomes uneconomical because the amount of the compounding is required to be large, and if it is more than 70% by weight, the viscosity becomes too high. Becomes difficult to handle because it becomes high, so in the range of 1 to 70% by weight, preferably 10 to 60% by weight
It is better to set the range. The silicone granules can be mixed with curable silicone in advance, so that oil, silane, organic powder, inorganic powder or the like can be contained in the particles.

The above-mentioned first to fifth components are mixed prior to use, but it is also possible to mix the above components in advance to prepare a 2-4 component system. In that case, for example, the first component, the second component, and the third component, or the first component, the second component, the third component, and the fifth component can be mixed. If the effective amount of the first component is less than 10% by weight, the abrasion resistance is poor, and if it exceeds 90% by weight, the adhesion to the rubber surface is reduced and the abrasion resistance is poor. If the effective amount of the second component is less than 0.1% by weight, the curability of the film will be reduced, and if it exceeds 50% by weight, the abrasion resistance will be poor. If the effective amount of the third component is less than 0.1% by weight, the film will be inferior. The curability of is decreased, and if it exceeds 50% by weight, the abrasion resistance is poor. If the amount of the active ingredient of the fourth component is less than 1%, the adhesion to the rubber surface will be deteriorated, and if it exceeds 50% by weight, the abrasion resistance will be poor, and if the amount of the active ingredient of the fifth component is less than 1% by weight, the surface will be inferior. The smoothness is low, and if it is more than 70% by weight, the wear resistance is poor.
The blending ratio of these components is such that the active ingredient weight ratio is the first component / second component / third component / fourth component / fifth component = 10 to 90% by weight / 0.1.
To 50% by weight / 0.1 to 50% by weight / 1 to 50% by weight / 1 to 70% by weight, more preferably the first component / second component / third
Component / fourth component / fifth component = 20 to 70% by weight / 0.5 to 10% by weight / 0.5 to 10% by weight / 5 to 40% by weight / 5 to 50% by weight.

The mixing of the first to fifth components may be carried out by using a conventionally known mixing stirrer having paddle type, anchor type, etc. stirring blades. If it is less than 1% by weight, the coating film on the rubber article will be thin and the abrasion resistance will be poor, and if it is more than 50% by weight, the stability of the aqueous emulsion will decrease. It is preferably in the range of 50% by weight, preferably 10 to 30% by weight,
It is preferable to dilute with water if necessary.

As the rubber material to which the surface treatment with the aqueous emulsion of the first to fifth components is applied, natural rubber, EPD
Examples thereof include M, SBR, chloroprene rubber, isoprene-isobutylene rubber, and nitrile rubber, and the rubber article made of these rubber materials may have a sponge shape, a solid shape, or the like. As a surface treatment method for a rubber article, a mixed liquid of the first component to the fifth component is applied by brushing,
After coating by a method such as spray coating, roll coating, dip coating, or knife coating, the coating may be cured at room temperature or by heating and drying, which makes it possible to easily obtain the target surface-treated rubber article. it can.
Examples of the surface-treated rubber article thus obtained include sealing materials such as O-rings, gaskets and various packings, and rubber hose materials, and can be widely applied to others.

In order to accelerate the hardening of the film in this surface treatment, organic acid such as dibutyltin dilaurate, dioctyltin laurate, dibutyltin diacetate, tin octylate, iron octylate, zinc octylate is added to the treating agent. Compounding a metal salt, within the range that does not impair the effects of the present invention, carbon black, fluororesin powder, melamine resin powder, acrylic resin powder, polycarbonate resin powder, silicone resin powder, nylon resin powder, if necessary. It is optional to add graphite powder, various organic or inorganic pigments, paraffin wax, polyethylene wax, silicone oil, etc. to the treatment agent.

[0029]

[Examples] Next, preparation examples, examples and comparative examples of the first to fifth components used in the present invention will be described. The viscosity in the examples indicates a measured value at 25 ° C, and% is Indicates weight percent. In addition, the methods for evaluating the wear resistance and surface smoothness of the rubber article surface in the examples are based on the measurement results by the following methods. (Evaluation of wear resistance) EPDM sponge rubber (10 mm x 1
50 mm) ground glass cell shown in Fig. 1 (line contact, line width 5
mm), with a thrust load of 350 g, friction speed: 60
Reciprocation / minute, friction stroke: When performing reciprocal friction under the condition of 70 mm, the number of frictions until the rubber base material is exposed is measured. (Evaluation of surface smoothness) EPDM sponge rubber (10 mm x
50mm) two pieces on a steel plate (50mm x 50mm) as shown in Fig. 2, and as shown in Fig. 3, a dynamic friction coefficient measuring device is used to apply a load of 1kg and a pulling speed of 100mm /
The coefficient of dynamic friction with the glass was measured under the condition of minutes.

(Preparation Example 1-Preparation of first component-1) 350 g of octamethylcyclotetrasiloxane and 1.3 g of phenyltriethoxysilane were placed in a 1 liter glass beaker and mixed with stirring with a homomixer at 2,000 rpm. Ten%
When 35 g of sodium lauryl sulfate aqueous solution and 35 g of 10% dodecylbenzene sulfonic acid aqueous solution were added and stirring was continued at 6,000 rpm, phase inversion occurred and thickening was observed, but 280 g of water was added while still stirring at 2,000 rpm. In addition,
Then, it was passed through a high-pressure homogenizer of 300 kg / cm ² , and a stable O / W type emulsion was obtained. Next,
This emulsion was transferred to a glass flask with a volume of 1 liter equipped with a stirrer, a thermometer and a reflux condenser and heated at 50 ° C for 12 hours.
After reacting for 20 hours, aging at 25 ℃ for 24 hours, then 10%
When neutralized with an aqueous solution of sodium carbonate, an aqueous emulsion containing a branched silicone (hereinafter referred to as a first component-1) was obtained. After adding isopropyl alcohol to this to break the emulsion, The siloxane was extracted and dried to give a gel-like non-flowable siloxane. The active ingredient content of this aqueous emulsion is 49%.

Preparation Example 2 Preparation of First Component-2 Octamethylcyclotetrasiloxane 333 g, N- (β-aminoethyl) -γ-aminopropylmethylpolysiloxane 1
4 g and 3 g of methyltriethoxysilane were placed in a 1 liter glass beaker and mixed with stirring with a homomixer at 2,000 rpm, 30 g of 30% cetyltrimethylammonium chloride aqueous solution, polyoxyethylene (the number of added moles = 60).
Mol) nonyl phenyl ether 3g, water 70g 6,
When the stirring was continued at 000 rpm, phase inversion occurred and thickening was observed, but 520 g of water was added while stirring at 2,000 rpm as it was, and then passed through a 300 kg / cm ² high-pressure homogenizer, and a stable O A / W emulsion was obtained. Next, this emulsion was mixed with a stirrer, a thermometer,
Transfer to a 1-liter glass flask equipped with a reflux condenser, add 20 g of 5% potassium hydroxide aqueous solution, and add 72% at 70 ° C.
After reacting for an hour, the mixture was aged at 25 ° C. for 24 hours and then neutralized with acetic acid to obtain an aqueous emulsion containing a branched silicone (hereinafter referred to as a first component-2). Therefore, isopropyl alcohol was added to this to break the emulsion, and then the siloxane was extracted and dried to obtain a gel-like non-fluidic siloxane. The active ingredient content of this aqueous emulsion is 35%.

Preparation Example 3 Preparation of Second Component-1 2 g of hydrochloric acid (concentration 35%) and 190 g of deionized water were added to a glass flask of 1 liter capacity equipped with a stirrer, a dropping device, a thermometer and a reflux condenser. Γ-glycidoxypropylmethyldiethoxysilane (270 g) was added dropwise over 3 hours with stirring at 50 ° C. After completion of the addition, the mixture was neutralized with propylene oxide and the reaction system was depressurized while heating. The produced ethanol was distilled off, and the pressure-reducing operation was continued at 100 ° C. for 30 minutes, followed by cooling and returning to normal pressure, whereby a hydrolyzed condensate was obtained. Then, 315 g of this hydrolysis-condensation product, polyoxyethylene (the number of addition moles = 85 moles) nonyl phenyl ether 3
When 0 g and 70 g of water were charged into a 1 liter glass beaker and stirred and mixed at 6,000 rpm with a homomixer, thickening was observed, but 285 g of water was added while stirring at 2,000 rpm as it was. Was passed through a 300 kg / cm ² high-pressure homogenizer to obtain an aqueous emulsion (hereinafter referred to as the second component-1). The active ingredient content of this aqueous emulsion is 45%.

Preparation Example 4-Preparation of Third Component-1 γ-
(N-β-aminoethyl) aminopropylmethyldimethoxysilane (500 g) was placed in a glass flask having a capacity of 1 liter equipped with a stirrer, a dropping device, a thermometer, and a reflux condenser, and 135 g of deionized water was stirred at room temperature. After dropping for 30 minutes, the reaction system was depressurized while raising the temperature after the dropping, and the produced methanol was distilled off. Then, after continuing the depressurization operation at 55 to 60 ° C. for 30 minutes, the reaction was terminated by cooling and returning to normal pressure to obtain the hydrolyzed condensate 10.
5 g of water was charged into a 1-liter glass flask charged with 595 g of water at room temperature and stirred for 30 minutes to obtain an aqueous dispersion of this hydrolysis-condensation product (hereinafter referred to as third component-1). The content of the active ingredient in this product is 15%.

(Preparation Example 5-Preparation of fifth component-1)

[Chemical 7] 280g of methyl vinyl siloxane with a viscosity of 10cS
When,

[Chemical 8] 90g of methylhydrogenpolysiloxane with a viscosity of 200cS is charged into a glass beaker with a capacity of 1 liter and mixed with stirring at 2,000rpm using a homomixer. Then, polyoxyethylene (number of added moles = 9 moles) octyl phenyl ether When 3 g and 70 g of water were added and stirring was continued at 6,000 rpm, phase inversion occurred and thickening was observed.
Further, while stirring at 2,000 rpm as it is, 295 g of water
Was added, an O / W type emulsion was obtained. Then, this emulsion was transferred to a glass flask equipped with a stirrer and stirred at room temperature with 1 g of a toluene solution of a chloroplatinic acid-olefin complex (platinum content: 0.05%) and polyoxyethylene (the number of added moles = 9 mol) octyl. When a mixture of 1 g of phenyl ether was added and the reaction was carried out for 12 hours, an aqueous dispersion (hereinafter referred to as the fifth component-1) was obtained. The average particle size of the particles in this dispersion was determined by a Coulter counter ( It was 4 μm as measured by Coulter Electronics Co., Ltd., and several g of this dispersion was dried at room temperature to obtain an elastic white rubber powder. The active ingredient content of this aqueous dispersion is 50%.

(Preparation Example 6-Preparation of Fifth Component-2) 0.5 g of polyoxyethylene (addition mole number = 9 moles) octyl phenyl ether 3 g used in the preparation of the O / W type emulsion in Preparation Example 5 was set to 0.5 g. Except that the treatment was performed in the same manner as in Preparation Example 5 to obtain an aqueous dispersion (hereinafter referred to as the fifth component-2.
The average particle size of the particles in this dispersion was 13 μm. When several g of this dispersion was air dried, an elastic white rubber powder was obtained.
The active ingredient content of this aqueous dispersion is 50%.

Examples 1 to 6 The first to fifth components obtained in Preparation Example were mixed in the composition shown in Table 1 to prepare a surface treating agent composition, and these were treated with EP.
The surface of DM sponge rubber (thickness: 2 mm) was applied with a brush and left for 10 minutes in a hot-air circulation type thermostat controlled at 150 ° C to perform surface treatment. Then, the surface-treated sponge rubber thus obtained is subjected to a friction test, and the abrasion resistance is evaluated by measuring the number of frictions until the sponge rubber base material is exposed, and its dynamic friction coefficient is measured. When the surface smoothness was evaluated, the results as shown in Table 1 were obtained, and all of them showed excellent results with respect to the adhesion, abrasion resistance and surface smoothness of the coating.

[0037]

[Table 1]

Comparative Examples 1 to 4 The surface treatment agent compositions were prepared by mixing the first to fifth components obtained in Preparation Examples with the composition shown in Table 2, and using these, the same as in Examples. The surface treatment of the sponge rubber was carried out by the method, and the friction test and the dynamic friction coefficient of the obtained surface-treated sponge rubber were measured, and the results as shown in Table 2 were obtained.

[0039]

[Table 2] When the fourth component is not added as in Comparative Example 1, the adhesion, wear resistance and surface smoothness are poor, and when the fourth component is excessive as in Comparative Example 2, the wear resistance is poor. It was confirmed that the surface smoothness was poor with the addition of the fifth component as in Comparative Example 3, and the wear resistance was poor with only the fourth and fifth components as in Comparative Example 4. It was

[0040]

The surface treatment agent of the present invention can form a silicone resin film having excellent adhesion, abrasion resistance and surface smoothness on a rubber article. The rubber article treated with the surface treatment agent of the present invention is suitable for applications in which frictional force is repeatedly applied.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an outline of a method of measuring wear resistance.

FIG. 2 is an explanatory diagram showing an outline of a test piece for measuring a dynamic friction coefficient.

FIG. 3 is an explanatory diagram showing an outline of a method of measuring a dynamic friction coefficient.

[Explanation of symbols]

 1 EPDM sponge rubber 2 Ground glass cell 3 Steel plate 4 Glass plate

Claims (2)

[Claims] 1. A general formula R ¹ ₂ SiO _2/2 as a first component
R ¹ SiO _3/2 (wherein R ¹ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 20 carbon atoms) as a constitutional unit, an aqueous dispersion of a non-fluidic branched silicone, 2) The general formula R ² SiR ³ (OR ⁴ ) ₂ as two components (where R ²
Is an epoxy group-containing monovalent organic group having 5 to 20 carbon atoms, R
³ , R ⁴ is an aqueous emulsion of a hydrolysis-condensation product of a dialkoxysilane represented by an unsubstituted or substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, 3) the general formula R ⁵ as the third component R ⁶ N (CH ₂ ) _a [NR ⁷ (CH ₂ ) _b ] _c
SiR ⁸ (OR ⁹ ) ₂ (wherein R ⁵ , R ⁶ , and R ⁷ are each a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, and R ⁸ and R ⁹ are each 1 carbon atoms. To 6 unsubstituted or substituted monovalent hydrocarbon groups, a, b and c are 1 ≦ a ≦ 6 and 1 ≦ b ≦
6, 0 ≦ c ≦ 3) Aqueous dispersion of hydrolysis-condensation product of dialkoxysilane, 4) General formula R ¹⁰ Si (OR ¹¹ ) ₃ (where R ¹⁰
Is a (meth) acrylic group-containing monovalent organic group having 5 to 20 carbon atoms, and R ¹¹ is a trialkoxysilane represented by an unsubstituted or substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, or a general formula
R ¹² R ¹³ N (CH ₂ ) _d [NR ¹⁴ (CH ₂ ) _e ] _f Si (OR ¹⁵ ) ₃ (where R ¹² ,
R ¹³ and R ¹⁴ are each hydrogen or a group selected from a monovalent hydrocarbon group having 1 to 6 carbon atoms and a halogenated hydrocarbon group;
¹⁵ is a group selected from a monovalent hydrocarbon group having 1 to 6 carbon atoms and a halogenated hydrocarbon group, and 1≤d≤6, 1≤e
≦ 6, 0 ≦ f ≦ 3) Trialkoxysilane, 5) A surface treatment agent for a rubber article, which is obtained by mixing 5 components of 5) an aqueous dispersion of silicone rubber granules as a 5th component. 2. The weight ratio of the active ingredients in the first to fifth components according to claim 1 is 1st component / 2nd component / 3rd component / 4th component / 5th component = 10 to 90% by weight / 0.1 to 50% by weight / 0.1 ~
50% by weight / 1-50% by weight / 1-70% by weight
The surface treatment agent for a rubber article as described in 1.