JP2000063749A - Surface treating agent for gas barrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a surface treating agent for gas barrier having excellent gas barrier property, excellent in transparency, flexibility and weather ability, and having discoloration with time suppressed as much as possible. SOLUTION: This surface treating agent mainly contains a silicone resin- containing emulsion prepared by the emulsion polymerization of a mixed solution consisting of (a) 100 pts.wt. of the below-mentioned silanol group-containing silicone resin having a number average molecular weight of 500 or more, and (b) 10-1000 pts.wt. of a radical polymeric vinyl monomer. The silanol group- containing silicone resin contains 30-100 mol.% of a structural unit (T unit) expressed by the formula R1SiZ3, and in the T-unit, a structural unit (T-2 unit) expressed by the formula, R1Si(OH)Z'2 [R1 is a (substituted) monovalent hydrocarbon group; and Z is OH, a hydrolyzing group or a siloxane residue] having one silanol group is 30-80 mol.%.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a surface treatment agent for a gas barrier used for packaging materials and the like.

[0002]

2. Description of the Related Art Conventionally, gas barrier materials having a low gas permeability such as oxygen, nitrogen, carbon dioxide and water vapor have been used in the field of packaging materials and the like. As a gas barrier material, a plastic film or sheet having a gas barrier property is known. As such a gas barrier material, ethylene-vinyl alcohol copolymers, vinylidene chloride copolymers, those using gas impermeable materials such as polymetaxylylene adipamide, those gas impermeable materials Of the above materials, aluminum foil laminated to a film material, metal oxide vapor deposited, and the like.

However, when ethylene-vinyl alcohol copolymer or polymeta-xylylene adipamide is used as the gas impermeable material, since these have large hygroscopicity, the gas barrier property is lowered by moisture absorption, and vinylidene chloride-based copolymers are used. If a polymer is used, it contains chlorine atoms and thus poses a problem in terms of environmental pollution. On the other hand, the aluminum foil laminated film has a problem that the content is not visible from the outside because it is opaque, and the metal vapor deposition film is inferior in flexibility, and the vapor deposition layer is easily cracked to deteriorate the gas barrier property. It was

On the other hand, it is also known that a surface treatment of a plastic film is carried out by using polysiloxane having a dense molecular structure such as tetraalkoxysilane and having excellent weather resistance, hardness and chemical resistance. And this is transparency,
Although it is excellent in weather resistance and the like, tetraalkoxysilane has a problem that a volume shrinkage rate during condensation is large and cracks and pinholes are generated.

In this case, it has been proposed to hydrolyze and condense the alkoxysilane to cover the plastic film (Japanese Patent Laid-Open No. 2-286331), but since this is a coating of only the alkoxysilane component, the film There was a problem of poor flexibility.

Therefore, in order to improve flexibility, a composition obtained by adding an emulsion-polymerized water dispersion of acrylic acid ester to an aqueous solution of γ-aminopropyltriethoxysilane has been proposed as a surface treatment composition for gas barrier. (JP-A-7-
3206 publication). This composition has improved flexibility and has an advantage as a water-based coating material, but since it uses an aminosilane hydrolyzate, it has a reactive amino group and changes color to yellow over time due to oxygen. There was such a problem.

Therefore, the present invention has an excellent gas barrier property,
It is an object of the present invention to provide a water-based surface treatment agent for gas barriers which is transparent, has flexibility, is excellent in weather resistance, has no risk of discoloration over time, and is excellent in safety.

[0008]

Means for Solving the Problems and Modes for Carrying Out the Invention As a result of intensive studies for achieving the above-mentioned object, the present inventor has found that a silanol group-containing silicone resin of the following component (a) and a component (b) By emulsion-polymerizing the mixed solution containing the radical-polymerizable vinyl monomer as a main component, a solvent having a boiling point of less than 100 ° C. such as alcohol or ketone and an aromatic organic solvent such as benzene, toluene, xylene are not substantially contained. , A condensation type silicone resin and a vinyl polymer resin are contained in the same particle of the emulsion to obtain an emulsion having excellent storage stability and good coating properties, and the coating film obtained from this is transparent and flexible. Therefore, the present invention has been made, and it was found that the gas barrier property is excellent, the weather resistance is good, and the color does not change with time. Than it is.

Therefore, the present invention is based on the formula (a). R¹-SiZ₃
Containing 30 to 100 mol% of a structural unit (T unit) represented by
And of this T unit, the formula R¹-Si (OH)
Z '₂Structural unit containing one silanol group represented by
(T-2 unit) 30 to 80 mol% (provided that the above
Where R¹Represents a substituted or unsubstituted monovalent hydrocarbon group,
Z represents an OH group, a hydrolyzable group or a siloxane residue,
Z'represents a siloxane residue. ), The number average molecular weight is 50
100 or more silanol group-containing silicone resin of 0 or more
Parts, and (b) radically polymerizable vinyl monomer 10 to 1
Obtained by emulsion polymerization of a mixed solution containing 000 parts by weight.
Silicone resin-containing emulsion
A surface treatment agent for a water-based gas barrier characterized by having
I will provide a.

The present invention will be described in more detail below. The gas barrier surface treating agent of the present invention is a silicone resin-containing emulsion obtained by emulsion polymerization of a mixed solution of a silanol group-containing silicone resin and a radically polymerizable vinyl monomer. The main component.

Here, the silanol group-containing silicone
The resin is of formula (i) : R¹-SiZ₃Structural unit represented by
(T unit) is contained in an amount of 30 to 100 mol%, and
Out of rank : R¹-Si (OH) Z '₂Shira represented by
A structural unit (T-2 unit) containing only one norl group
30 to 80 mol% is contained, (ii) number
An average molecular weight of 500 or more, preferably (iii)
Satisfies the condition of containing at least 5% by weight of silanol groups.
A silanol group-containing silicone resin to be added.

In the above formula, R ¹ represents a substituted or unsubstituted monovalent hydrocarbon group. The unsubstituted monovalent hydrocarbon group preferably has 1 to 10 carbon atoms, and is a methyl group, ethyl group, propyl group, isopropyl group, butyl group, t-butyl group, hexyl group, cyclohexyl group, octyl group, decyl group. Specific examples include an alkyl group such as a group, a vinyl group, an allyl group, an alkenyl group such as a 5-hexenyl group, a 9-decenyl group, and an aryl group such as a phenyl group. Among these, a methyl group, a propyl group, a hexyl group, and a phenyl group are preferable. In particular, when weather resistance is required, a methyl group is preferable, when water repellency is required, a long-chain alkyl group is preferably used, and when imparting flexibility to a coating, a phenyl group is applied. Is good. In this case, it is particularly preferable that the content of methyl groups in all the organic group substituents is at least 50 mol%, particularly 80 mol% or more.

Further, the substituted monovalent hydrocarbon group is the above-mentioned unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms in which some or all of the hydrogen atoms are substituted with a substituent excluding an amino group. Are (i) halogen atoms such as fluorine and chlorine,
(Ii) Glycidoxy group, epoxy functional group such as epoxycyclohexyl group, (iii) Methacrylic group, (meth) acryl functional group such as acrylic group, (iv) Sulfur-containing functional group such as mercapto group, tetrasulfide group, (v )
An alkyl ether functional group such as a (polyoxyalkylene) alkyl ether group, an anionic group such as (vi) a carboxyl group or a sulfonyl group can be applied.
Specific examples of the substituted monovalent hydrocarbon group include trifluoropropyl group, perfluorobutylethyl group, perfluorooctylethyl group, 3-chloropropyl group,
2- (chloromethylphenyl) ethyl group, 3-glycidyloxypropyl group, 2- (3,4-epoxycyclohexyl) ethyl group, 5,6-epoxyhexyl group, 9,1
0-epoxydecyl group, 3- (meth) acryloxypropyl group, (meth) acryloxymethyl group, 11- (meth) acryloxyundecyl group, 3-mercaptopropyl group, 2- (4-mercaptomethylphenyl) Examples thereof include an ethyl group, a polyoxyethyleneoxypropyl group and a 3-hydroxycarbonylpropyl group.
To improve the adhesion to the substrate, it is preferable to apply epoxy, mercapto functional group or the like. In the case of aiming at close blocking with a vinyl polymer, it is preferable to use a (meth) acrylic functional group capable of radical copolymerization or a mercapto functional group having a function as a chain transfer agent. When attempting to crosslink the vinyl polymer with a bond other than the siloxane bond, a functional group capable of reacting with the organic functional group contained in the vinyl polymer may be introduced.
For example, an epoxy group (reaction with a hydroxy group, an amino group, a carboxy group, etc.) and the like can be mentioned.

In the above formula, Z represents an OH group, a hydrolyzable group or a siloxane residue, and Z'represents a siloxane residue. Specific examples of the hydrolyzable group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, an alkoxy group such as a t-butoxy group, and an alkenoxy group such as an isopropenoxy group.
Examples thereof include an acyloxy group such as a phenoxy group and an acetoxy group, an oxime group such as a butanoxime group, and an amino group. Of these, an alkoxy group is preferable, and a methoxy group, an ethoxy group, an isopropoxy group, and a butoxy group are particularly preferable because they can be easily controlled during hydrolysis / condensation. In addition, a siloxane residue means a substituent which is bonded to an adjacent silicon atom through an oxygen atom to form a siloxane bond and can be represented by —O—Si≡.

In the present invention, the formula R¹-SiZ₃Represented by
The T unit has a large degree of crosslinking and curability of the silicone resin.
A structural unit that influences, containing 30 to 100 mol%
It When the content is less than 30 mol%, the formed film is low.
It has hardness and poor curability. Within the emulsion particles
An active sill that evenly entangles with vinyl polymer
Use silicone resin to control the degree of freedom
It is necessary to give more structure. T unit content is 50
~ 100 mol% range, silicone resin
Since the fat becomes rigid and the storage stability is good, it is even better.
Good

In this case, the other structural unit is R
¹ ₃SiZ M unit represented by 0 to 10 mol%, R¹ ₂SiZ
₂D unit represented by 0 to 50 mol%, or SiZ_FourRepresented by
You may use together Q unit 0-30 mol%. Hardened film
In order to further increase the hardness of
On the contrary, for the purpose of giving flexibility to the cured film,
It is preferable to use D units together.

In the silanol group-containing silicone resin of the present invention, R ¹ --Si in the T unit of R ¹ --SiZ ₃ is used.
It is necessary to contain 30 to 80 mol% of the T-2 unit containing only one silanol group represented by (OH) Z ' ₂ . In this case, since the siloxane residue represented by Z ′ can be represented by —O—Si≡ as described above, the T-2 unit is R ¹ —Si (OH) (— O—Si).
It can also be expressed as ≡) ₂ .

In order to ensure a certain hardness in the cured coating, it is necessary to contain a certain amount of T units, but good curability and good mutual solubility with the vinyl polymer formed in the particles. In order to secure flexibility and to impart flexibility to the cured coating, the T-2 unit in the T unit is 30 to 30%.
It is necessary to contain 80 mol%. If the content of the T-2 unit is less than 30 mol%, the absolute amount of silanol groups that contribute to the curing of the silicone resin will be insufficient, and the hardness of the cured coating will be insufficient. In order to obtain a resin in which the content of T-2 units exceeds 80 mol%, it is necessary to suppress the degree of polymerization to a low level, but with a low degree of polymerization, it is difficult to form a chain or cyclic structure.
As a result of the crystallinity of the cured film becoming high, the flexibility becomes insufficient and the degree of freedom in the particles becomes high, resulting in a decrease in storage stability. More preferably, this T-2 unit is 35 in all T units.
˜70 mol%.

Next, the number average molecular weight of the silanol group-containing silicone resin applied in the present invention will be described. It is necessary to impart a certain structural property to the silicone resin in order to obtain the above-mentioned various properties. . In order to secure its structural properties, the silicone resin must be polymerized to some extent. In this respect, it is necessary to use a silicone resin having a number average molecular weight of 500 or more in the present invention. If it is less than 500, appropriate structural properties cannot be ensured, so that good flexibility cannot be obtained and storage stability is poor. More preferably, the number average molecular weight is 1000 or more. The upper limit of the number average molecular weight is not particularly limited, but is usually about 50,000.

The silicone resin applicable to the present invention preferably satisfies the above conditions and at the same time contains a certain amount or more of silanol groups.
It is preferable that the content is not less than wt%, particularly 6 to 20 wt%. If the amount is less than 5% by weight, the absolute amount of silanol groups that contribute to crosslinking is insufficient, so that the hardness of the cured film may decrease.

The silicone resin may be produced by any method as long as the above conditions are satisfied.

Next, the radical polymerizable vinyl monomer as the second component will be described. As the radically polymerizable vinyl monomer, the following conventionally known ones can be applied as long as they are radically polymerizable. (A) Alkyl (meth) acrylate having 1 to 18 carbon atoms in the alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, octyl, 2-ethylhexyl, lauryl, stearyl or cyclohexyl ester of acrylic acid or methacrylic acid Ester, (b) carboxyl group such as acrylic acid, methacrylic acid, maleic anhydride or vinyl monomer containing anhydride thereof, (c) hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate Containing vinyl monomer, (d) (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth)
Amide group-containing vinyl monomers such as acrylamide, N-butoxymethyl (meth) acrylamide and diacetone (meth) acrylamide, amino group-containing vinyl monomers such as (e) dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate,
(F) Alkoxy group-containing vinyl monomers such as methoxyethyl (meth) acrylate and butoxyethyl (meth) acrylate, (g) glycidyl (meth) acrylate, glycidyl group-containing vinyl monomers such as glycidyl allyl ether, (h) vinyl acetate, Vinyl ester monomers such as vinyl propionate, (i) styrene,
Aromatic vinyl monomers such as vinyltoluene and α-methylstyrene, vinyl cyanide monomers such as (j) (meth) acrylonitrile, vinyl halide monomers such as (k) vinyl chloride and vinyl bromide, (l) divinylbenzene, A vinyl monomer containing two or more radically polymerizable unsaturated groups in one molecule such as allyl (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, and trimethylolpropane tri (meth) acrylate. (M) a (poly) oxyethylene chain-containing vinyl monomer such as (poly) oxyethylene mono (meth) acrylate having 1 to 100 ethylene oxide groups, and (n) a (meth) acryloxypropyl group at one end. Dimethyl polysiloxane contained, at one end Having a styryl group or α- -methylstyryl one end to the radical polymerizable functional groups such as dimethyl polysiloxane containing group, siloxane units 1
To 200 diorganopolysiloxanes, (o) hydrolyzable silanes containing vinyl-polymerizable functional groups of formula (1) described below, such as vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxy. Silane, 5-hexenyltrimethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, 3- (meth) Silane compounds containing radically polymerizable functional groups such as acryloxypropylmethyldiethoxysilane, 4-vinylphenyltrimethoxysilane, 3- (4-vinylphenyl) propyltrimethoxysilane, 4-vinylphenylmethyltrimethoxysilane, 2, 2, 6, - can be exemplified vinyl monomers containing a hindered base, such as tetramethyl-4-piperidinyl group Specific examples of them can be used alone or in combination of two or more.

Among these, the radically polymerizable vinyl monomer has an alkyl group having 1 to 18 carbon atoms (meth)
The content of the alkyl acrylate ester is preferably 1 to 100 mol%. If the content is less than 1 mol%, properties such as chemical resistance may not be obtained. It is more preferable to satisfy the range of 30 to 99 mol%. When imparting properties such as solvent resistance or chemical resistance to the cured film, it is preferable to copolymerize a radically polymerizable vinyl monomer having a crosslinkable functional group, and especially to form a siloxane bond by a condensation reaction. A silane compound containing a radically polymerizable functional group represented by (o), and a glycidyl (meth) acrylate classified as (g) having an epoxy functional group capable of crosslinking by a ring-opening reaction of a carboxylic acid / epoxy group, A glycidyl group-containing vinyl monomer such as glycidyl allyl ether is suitable, and since the resin used for the other in the present system is a silanol group-containing silicone resin, a silane compound is more suitable. In this case, a vinyl-polymerizable functional group-containing hydrolyzable silane represented by the following general formula (1) is used as the silane compound.

[0024]

[Chemical 1] In the formula, R ² is a hydrogen atom or a methyl group, and R ³ has 1 to 1 carbon atoms.
0 oxygen atom, a divalent organic group such as an alkylene group, an arylene group or an alkylenearylene group, which may have an oxygen atom-containing group such as a -COO- group, Y is a hydrolyzable group, and r is 0. , 1 or 2 and R ¹ has the same meaning as above.

Specific examples of R ³ include the following.

[0026]

[Chemical 2]

The above-mentioned hydrolyzable group of Y can be the same as those mentioned above.

The content of the above-mentioned vinyl-polymerizable functional group-containing hydrolyzable silane is preferably 0.01 to 10 mol%, particularly preferably 0.1 to 5 mol%, of the whole radical-polymerizable vinyl monomer. If the amount is too small, the crosslinking with the silicone resin may be insufficient, and if the amount is too large, the cured coating becomes too hard and good flexibility may not be obtained, which may be inappropriate.

When it is desired to impart lubricity to the surface, it is preferable to copolymerize a diorganopolysiloxane containing a radically polymerizable functional group at one end, as exemplified in (n).

The radical polymerizable vinyl monomer is added to 1 part by weight of 100 parts by weight of the first component silicone resin.
It is used in the range of 0 to 1000 parts by weight. If it is less than 10 parts by weight, the film-forming property and chemical resistance may be insufficient,
If it exceeds 1000 parts by weight, weather resistance and water resistance may be insufficient. More preferably, the radical-polymerizable vinyl monomer is used in the range of 30 to 500 parts by weight.

Emulsion containing silicone resin of the present invention
Is the silanol group-containing silicone resin and the radical
Mainly composed of emulsion polymer with compatible vinyl monomer
However, the method for obtaining this emulsion polymer is (i)
The following formula R¹SiX₃ (In the formula, R¹Is the same as above, X is an alkoxy group, alk
Hydroxy of noxyl group, chloro atom, amino group, oxime group, etc.
Indicates a degradable group. ) The silane represented by
% (Containing the balance SiX_Four, R¹ ₂SiX₂, R¹ ₃Si
X ) Hydrolyzable silane compound in an aqueous solution of pH 1-7
Hydrolyzed and containing the silanol group-containing silicone resin
Obtaining a reaction mixture, (ii) from this reaction mixture
Hydrolysis by-products are removed to the outside of the system, mainly silanol
A step of forming a system containing a group-containing silicone resin and water,
(Iii) Mainly silanol group-containing silicone resin
A radically polymerizable vinyl monomer is added to the system consisting of fat and water.
Add the silanol group-containing silicone resin to the vinyl
Dissolve the remaining hydrolysis by-product and water in the monomer.
Removing step, (iv) this silicone resin-containing boom
Solution of a polymerizable vinyl monomer with a surfactant, preferably
Is a reactive surfactant (JP-A-8-27347).
It can be obtained by a step of emulsion polymerization in the presence.

The above silicone resin-containing emulsion composition has the following characteristics. (I) Since vinyl monomers are polymerized in the presence of silicone resin in the emulsion particles, both resins form an interpenetrating network structure (IPN). As a result, even if a methyl-based silicone resin having poor mutual solubility is used, a film having excellent transparency is formed, and the shortage in the characteristics of both resins is complemented. In particular, since a large amount of silicone resin, which is rich in hardness, chemical resistance, and weather resistance, can be contained, the formed film has excellent film-forming properties and good properties such as scratch resistance, weather resistance, and chemical resistance. It gives a uniform cured film having good flexibility. Further, it provides a good transparent protective film that does not cause blocking even with an uncured film that has just evaporated water. (Ii) In the emulsion particles, the polymers are entangled with each other in a solvent-free state, so that the degree of freedom of the silanol group having a high condensation activity is limited. As a result, condensation of silanol groups is suppressed and good storage stability is obtained. (Iii) When the silanol group having a specific structure is contained in a certain amount or more in the silicone resin, the silanol group is restrained in a good state in the emulsion particles, while its high curing activity is preserved and excellent at a relatively low temperature. Curability is secured. In addition, by containing a large amount of silanol groups having a specific structure, the number of linear structures increases, and the coating film can be imparted with contradictory properties such as flexibility and hardness. (Iv) Since a low boiling point organic solvent of less than 100 ° C. or an aromatic organic solvent such as toluene is not contained, a good working environment is secured. In addition, the stability of the emulsion is maintained in a good state because it does not contain an alcohol component that promotes the destruction of the emulsion or does not form a by-product. (V) By adding a conventionally known film-forming aid, a good film can be obtained during drying and curing. Further, when a specific curing catalyst is used in combination, room temperature curing is possible, and rapid curing is also possible at a relatively low temperature. (Vi) Therefore, it is possible to form a transparent and flexible film having these characteristics and having excellent gas barrier properties. Since this film does not discolor over time and has excellent weather resistance, it can be used as a surface treatment agent for gas barriers. It is valid.

The emulsion obtained above contains an emulsion polymer of the above silicone resin and a radically polymerizable vinyl monomer as a main component. This emulsion contains an organic solvent having a boiling point of less than 100 ° C. which is substantially flammable as described above,
Although it does not substantially contain an aromatic organic solvent which is harmful to the human body and a non-dispersible (non-water-soluble) organic solvent in water, the surface treatment agent of the present invention has a boiling point of 100 ° C., if necessary. The above water-soluble film-forming aid can be added in a proportion of 20 parts by weight or less based on 100 parts by weight of the total amount of the components (a) and (b).

Further, in order to improve the stability of the silicone resin-containing emulsion, an acidic compound such as a mineral acid or an organic acid, or a basic compound such as ammonia or an inorganic base can be added.

The emulsion according to the present invention can be crosslinked and cured by heating even without a catalyst, but for the purpose of accelerating the curing rate, enabling low temperature curing at room temperature level, or obtaining excellent film properties, If necessary, a silanol condensation catalyst may be added at the time of use. As this silanol condensation catalyst, conventionally known ones as curing catalysts for condensation can be used, but those which are highly safe for the environment and human body, such as baking soda and sodium acetate, are used. It is preferable to add 20 parts by weight or less to 100 parts by weight of the total amount of the components.

The surface treatment agent of the present invention has a pH of 3-1.
It can be 2.

The surface treating agent of the present invention is particularly effectively used for forming a gas barrier coating on a polyester film, a polyolefin film or the like. In this case, as the method for applying the surface treatment agent of the present invention, various conventionally known coating methods such as a dipping method, a spray method, a roll coating method and a brush coating method can be used. Further, in order to improve the adhesion between the object to be treated and the film, a primer treatment or a corona discharge treatment may be performed for coating. When used as a protective film in an uncured state, the coated substrate may be left at room temperature to evaporate water. When curing at room temperature to proceed with crosslinking to form a high hardness coating, a substrate coated with a surface treatment agent containing a condensation catalyst is left at room temperature for 0.1 to 30 days to obtain a good cured coating. . When the crosslinking is advanced by heat curing to form a high hardness coating, the substrate coated with the surface treatment agent containing no catalyst or condensation catalyst is maintained in the temperature range of 50 to 300 ° C. for 0.5 minutes to 200 hours. It is achieved by The thickness of the gas barrier coating of the surface treatment agent according to the present invention is appropriately selected, but it is 0.1 to 20 μm.
m, particularly preferably 0.2 to 1.5 μm.

[0038]

According to the present invention, the gas barrier property is excellent,
A transparent and flexible coating can be formed, and this coating is excellent in weather resistance and whose discoloration over time is suppressed as much as possible.

[0039]

[Examples] Hereinafter, Preparation Examples, Examples and Comparative Examples will be shown.
The present invention will be specifically described, but the present invention is not limited to the following examples. In the following examples, parts indicate parts by weight.

[Preparation Example] 408 g (3.0 mol) of methyltrimethoxysilane was charged into a 2-liter flask, and 800 g of water was added at 0 ° C. under a nitrogen atmosphere and mixed well. Here, under ice cooling, a 0.05N hydrochloric acid aqueous solution 216
g was added dropwise over 40 minutes to carry out a hydrolysis reaction. After completion of dropping, the mixture was stirred at 10 ° C. or lower for 1 hour and then at room temperature for 3 hours to complete the hydrolysis reaction.

Then, the methanol and water produced by hydrolysis were distilled off under reduced pressure for 1 hour at 70 ° C. × 60 Torr to obtain 1136 g of a solution. The solution is cloudy, 1
When left standing for 24 hours, it was separated into two layers, and the water-insoluble silicone resin settled.

A part of the cloudy solution was sampled, the water-insoluble silicone resin was dissolved using methyl isobutyl ketone, and separated from the aqueous layer. After the dehydration treatment, methyl Grignard was reacted and the silanol group was quantified. As a result, the silanol group content was 11.0% by weight (based on the silicone resin). As a result of GPC measurement, the number average molecular weight of this silicone resin was 1.8 × 10 ³ .

The structure of the silanol group-containing silicone resin was determined by infrared absorption spectrum analysis and ²⁹ NMR analysis. In the infrared absorption spectrum of the film from which the solvent was removed by air-drying, a broad absorption derived from the silanol group was observed centered on 3200 cm ⁻¹ , while at about 2840 cm ⁻¹ derived from the stretching vibration of the carbon-hydrogen bond of the methoxy group. No absorption was observed in. As an alternative method, the residual methoxy group was distilled off by an alkali cracking method to quantify it, but methanol was not detected, and the result of the infrared absorption spectrum analysis was confirmed. From this result, it was determined that the methoxy group was completely hydrolyzed.

In the ²⁹ NMR analysis, each structure of the T unit shown below can be discriminated from the difference in the position of the chemical shift that appears. T-1 units _{CH 3 -Si (-O-Si≡)} 1 (-OH)
_{2 -46~48ppm T-2} units _{CH 3 -Si (-O-Si≡)} 2 (-OH)
_{1 -54~58ppm} T-3 units _{CH 3 -Si (-O-Si≡)} 3
-62 to 68 ppm

^{29 of the} silanol group-containing silicone resin
When NMR analysis was performed, T-1 unit was 2 mol%, T
-2 units were found to contain 42 mol% and T-3 units contained in 56 mol%.

From the above analysis results, the obtained silicone resin can be represented by the following average composition formula. (CH ₃ ) _1.0 Si (OH) _0.44 O _1.28 The silanol group content calculated from this composition formula is 10.
It was 5% by weight, which is in good agreement with the measured value.

Next, 210 g of methyl methacrylate (MMA) and 90% of butyl acrylate (BA) were added to this aqueous solution.
g was added, the precipitated silicone resin was dissolved, and a silicone resin-containing MMA / BA solution was separated from the aqueous layer.
Water (500 g) was added to the separated solution, and the mixture was stirred and mixed for 10 minutes, and then allowed to stand to separate an aqueous layer. When the amount of methanol contained in the organic layer was quantified by GC, 0.2% by weight was detected in this solution. Finally, 505 g of an MMA / BA solution (A) having a nonvolatile content of 40.2% by weight (105 ° C x 3 hours) was obtained.

[Example] In a polymerization vessel equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet, 730 parts of deionized water, 0.47 parts of sodium carbonate as a pH buffer,
4.70 parts of boric acid was charged, the temperature was raised to 60 ° C. with stirring, and then the atmosphere was replaced with nitrogen. Rongalit 1.75
Parts, 0.12 parts of a 1% aqueous solution of disodium ethylenediaminetetraacetate and 0.04 parts of a 1% aqueous solution of ferrous sulfate, and at the same time, the silicone resin-containing MMA obtained in Preparation Example
/ BA solution (A) 700 parts, γ-methacryloxypropylmethyldimethoxysilane 7 parts, t-butyl hydroperoxide (pure content 69%) 2.1 parts, reactive surfactant Aqualon RN-20 (Daiichi Kogyo) A mixture of 49 parts manufactured by Pharmaceutical Co., Ltd. (trade name) was heated at a temperature of 60 in a polymerization vessel.
While maintaining the temperature at 0 ° C, the solution was added uniformly over 2.5 hours and further reacted at 60 ° C for 2 hours to complete the polymerization to obtain a silicone resin-containing emulsion.

Using this emulsion as a surface treating agent, a PET film having a thickness of 25 μm was applied with a bar coater to a thickness of 0.8 μm, and dried at 100 ° C. for 1 minute.

The surface-treated film obtained was transparent and had good adhesion, excellent flexibility, and an oxygen permeability of 3.25 cc /
It was m ² · 24 hr · atm. It was confirmed that there was no change even when this film was exposed to outdoor sunlight for 2 weeks, and that it had excellent weather resistance.

[Comparative Example] A four-necked flask equipped with a stirrer and a thermometer, 200 g of water, 0.6 g of sodium dodecylbenzene sulfonate, and 0.68 g of ammonium persulfate.
Was charged, the atmosphere was replaced with nitrogen gas, the temperature was raised to 80 ° C., and then 47.9 g of butyl acrylate and 49.6 g of methyl methacrylate.
g, 2.5 g of methacrylic acid, 30 g of water, 0.7 g of sodium dodecylbenzene sulfonate are mixed to obtain 3
It dripped continuously over time. After the dropping is completed, 1 at 80 ℃
After heating for an hour and cooling, it was filtered through a 200-mesh wire net to obtain an emulsion polymer.

Next, 20 g of γ-aminopropyltriethoxysilane was added to 80 g of water and stirred at 23 ° C. for 3 hours,
A clear liquid was obtained. To this liquid, 30 g of emulsion polymer is added.
The mixture was added dropwise over minutes to obtain a gas barrier surface treatment composition.

When this composition was treated in the same manner as in Example and exposed to outdoor sunlight for 2 weeks, the film turned yellow.

Continued front page    (72) Inventor Masaaki Yamatani             Gunma Prefecture Usui District, Matsuida Town             Shin-Etsu Chemical Co., Ltd. Silicone electronic materials             Inside the technical laboratory F-term (reference) 4F006 AA12 AA35 AB39 AB52 BA03                       BA05 DA00 DA04                 4F100 AH01A AH03A AK42 AK52A                       AT00B BA02 GB15 JD02                       JD02A JK07 JK17 JL09                       JM01A JN01 YY00A                 4J038 CC031 CC081 CF011 CF021                       CG031 CG081 CG141 CG161                       CG171 CH031 CH041 CH071                       CH121 CH141 CH171 CH201                       CL001 DB221 DL052 DL072                       DL092 DL112 DL122 NA08                       NA10 PB04 PC08

Claims (3)

[Claims] 1. Formula (a) R¹-SiZ₃The structure represented by
Unit (T unit) of 30 to 100 mol% and
Out of unit, expression R¹-Si (OH) Z '₂Shira represented by
30 structural units (T-2 unit) containing one norl group
~ 80 mol% (provided that in the above formula, R¹Is a substitution or
Indicates an unsubstituted monovalent hydrocarbon group, Z is an OH group, hydrolyzed
Group or siloxane residue, Z'is a siloxane residue
Indicates. ), A silanone having a number average molecular weight of 500 or more
100 parts by weight of a silicone resin containing a ru group, and (b)
10 to 1000 parts by weight of a polymerizable vinyl monomer
Containing a silicone resin obtained by emulsion polymerization of the mixed solution
Characterized by containing an emulsion as a main component
Surface treatment agent for gas barrier. 2. The surface treating agent according to claim 1, wherein the silanol group-containing silicone resin contains 5% by weight or more of silanol groups. 3. The surface treating agent according to claim 1, wherein the radical-polymerizable vinyl monomer contains 1 to 100 mol% of a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 18 carbon atoms. .