JPH02180964A - Releasing silicone composition and article coated therewith - Google Patents

Abstract

PURPOSE:To form a silicon composition which can give a cured film excellent in release characteristics and blocking resistance by adding colloidal silica to a well-known addition or condensation type releasing silicone composition. CONSTITUTION:A composition having a structure of the following addition or condensation type A or B: [A] a composition comprising 100 pts.wt. organopolysiloxane having at least two Si-bonded alkenyl groups in the mole cule, 0.2-50 pts.wt. organohydrogenpolysiloxane having at least three Si-bonded hydrogen atoms in the molecule, 0.1-10 pts.wt. nonaqueous colloidal silica and a catalytic amount of a platinum compound and [B] a composition containing 100 pts.wt. organopolysiloxane having at least two Si-bonded hydroxyls in the molecule, 0.5-20 pts.wt. organopolysiloxane or organosilane having at least two Si-bonded hydrolyzable groups in the molecule, 0.1-10 pts.wt. nonaqueous colloidal silica and a catalytic amount of a cure accelerator.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is a silicone composition for release, particularly for the production of film separators because it provides a cured film with good H release properties, dry touch, and excellent blocking resistance. The present invention relates to a release silicone composition that can be manufactured with good performance, and release papers and plastic molded articles coated with the same.

[Conventional technology] Base materials such as paper and plastic and adhesive substances! 1. It is well known that a release silicone composition is applied to the surface of the substrate to form a cured film thereon in order to facilitate separation and prevent adhesion between the substrates. This release silicone composition contains an organopolysiloxane having an alkenyl group bonded to a silicon atom in one molecule, an organopolysiloxane having a hydrogen atom bonded to a silicon atom in one molecule, and a platinum-based curing catalyst. an addition reaction type consisting of an organopolysiloxane having a hydroxyl group bonded to a silicon atom in one molecule; and an organopolysiloxane or organosilane having a hydrolyzable group bonded to a silicon atom in one molecule; A condensation reaction type product consisting of a curing accelerator is known [Issues to be solved] However, when the base material is highly smooth such as a plastic film, silicone treatment is required on both sides of the base material. If you try to apply this, there are problems such as wrinkles or uneven winding during the winding process after the coating process due to poor slippage between the coated film surface and its back surface or between the coated surfaces. In order to apply a silicone composition to the shell and form a removable cured film on the surface of the base material, it is usually 130%.
Heating at ~150°C for several tens of seconds is required, but if the base material has poor heat resistance, such as polyethylene, polypropylene, or vinyl chloride, a low temperature and short heat treatment is required. This disadvantageously results in insufficient curing of the silicone coating and blocking of the wound substrate.

Therefore, a method of adding a slip improver such as silicone powder to this silicone composition (Japanese Unexamined Patent Publication No. 1983-1989-1)
15848, JP-A-63-15849),
A method has been proposed in which silicone coating and film stretching are performed at the same time (see Japanese Patent Publication No. 60-30265), but this method of adding a slip improver tends to cause the slip improver to settle, resulting in poor adhesion of the cured film. This method has the disadvantage that it cannot be applied to substrates with poor heat resistance because the peeling properties and residual adhesion rate decrease. The disadvantage is that it cannot be applied to wood.

[Means for Solving the Problems] The present invention relates to a release silicone composition which solves the above disadvantages, and which includes: l) having at least two alkenyl groups bonded to a silicon atom in one molecule; 100 parts by weight of organopolysiloxane, 2) 0.2 to 50 parts by weight of organohydrodiene polysiloxane having at least three hydrogen atoms bonded to silicon atoms in one molecule, 3) 0.1 to 50 parts by weight of non-aqueous colloidal silica. 10 parts by weight, 4) a catalytic amount of a platinum-based compound, or a) 100 parts by weight of an organopolysiloxane having at least two hydroxyl groups in one molecule bonded to silicon atoms; 0.5 to 20 parts by weight of organopolysiloxane or organosilane having at least two hydrolyzable groups in one molecule; 8) 0.1 to 10 parts by weight of non-aqueous colloidal silica; 2) catalytic amount of curing. It is characterized by comprising a promoter.

That is, the present inventors conducted various studies in order to develop a release silicone composition that has good release properties and provides a cured film that is dry-touch and has excellent blocking resistance. Adding colloidal silica to a reactive silicone release composition prevents blocking between the front and back surfaces of a silicone-treated plastic substrate, and prevents blocking between the silicone-treated surfaces of a paper substrate that has both sides treated with silicone. We found that the texture of the coated surface becomes dry-touch, that wrinkles are prevented, and that the residual adhesion rate and peeling properties of the coated surface are improved. The present invention was completed by conducting research on the following.

This will be explained in further detail below.

[Function] As mentioned above, the release silicone composition of the present invention is a composition in which non-aqueous colloidal silica is added to a conventionally known addition reaction type or condensation reaction type release silicone composition. It consists of each component.

First, the organosiloxane as the first component constituting this known addition reaction type release silicone composition has at least two alkenyl groups bonded to a silicon atom in one molecule. may be at the end of the molecular chain or within the chain. Therefore, it may be a substantially linear diorganopolysiloxane in which the end of the molecular chain is an alkenyldimethylsilyl group or a trimethylsilyl group, and this alkenyl group Examples include vinyl group, allyl group, and butenyl group. In addition, organic groups bonded to silicon atoms other than this alkenyl group include alkyl groups such as methyl, ethyl, propyl, and butyl groups, aryl groups such as phenyl and tolyl groups, and carbon atoms of these groups. Preferably at least 50 mol% of monovalent hydrocarbon groups excluding unsubstituted or substituted aliphatic unsaturated groups of the same or different type, in which part or all of the hydrogen atoms bonded to are substituted with halogen atoms, cyano groups, etc.
is a methyl group, but this diorganopolysiloxane may be used alone or in a mixture of two or more types.

Further, the diorganopolysiloxane preferably has a viscosity of 50 cS or more from the viewpoint of coating workability and the performance of the film formed.

Furthermore, the organohydrodiene polysiloxane as the second component constituting this addition reaction type releasable silicone composition has at least three hydrogen atoms bonded to a silicon atom in one molecule; 50 of the total amount of those having two = SiH bonds in the molecule.
% by weight and the remainder is at least 3 =si in the molecule.
It is preferable to include an h bond. As this organopolysiloxane, (C)I3))lsio'L position,
HSiO+, s unit, (11:I(s) 2H5iO
0, unit homopolymer or with these CH35IO1
,s unit, (CH3)zsio unit, (CH3) ,s
io. , a copolymer containing 5 units, etc., which may be linear, cyclic, or branched, but preferably have a viscosity of 10 to 500 cS as measured at 25°C. The amount of polysiloxane added is preferably 0.2 to 50 parts by weight per 100 parts by weight of the first component, considering the formation of a cured film and the peeling performance of the film.

Note that the platinum-based compound as the fourth component constituting this addition reaction type releasable silicone composition may be one known as a catalyst for the addition reaction between the first component and the second component described above.
These include chloroplatinic acids such as chlorinated platinic acid and chlorinated platinic acid, alcohol compounds of chloroplatinic acid, aldehyde compounds, and complex salts of chloroplatinic acid and various olefins. However, in order to obtain a good cured film, and from an economical point of view, the platinum amount should be 1 to 1.00 (
It may be in the range of ippm, preferably in the range of 2 to 500 ppm.

Next, the organopolysiloxane as component (a) constituting this known condensation reaction type release silicone composition has at least two hydroxyl groups bonded to a silicon atom in one molecule; It may be straight or branched, and the organic group bonded to the silicon atom other than the hydroxyl group is the same alkyl group as the organic group other than the alkenyl group in the first component of the addition-reactive silicone composition, The aryl group or a group in which part or all of the hydrogen atoms bonded to its carbon atoms are substituted with a halogen atom, a cyano group, etc. may be used. Further, this organopolysiloxane may be used alone or as a mixture of two or more types, but it is preferable that this organopolysiloxane has a viscosity of 50 cS or more in view of its coating workability and the performance of the film formed.

In addition, the organopolysiloxane and organosilane that constitute this condensation reaction type silicone composition serve as crosslinking agents for curing this composition due to moisture in the air. has at least two hydrolyzable groups bonded to a silicon atom in one molecule, and these hydrolyzable groups include a hydrogen atom, a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples include alkoxy groups, acyloxy groups, amino groups, aminoxy groups, ketoxime groups, etc.

Therefore, the organopolysiloxane is methylhydrodienepolysiloxane, and the luganosilane for this month is alkoxysilanes such as methyltrimethoxysilane and ethylsilicate, acyloxysilanes such as methyltriacetoxysilane and vinyltriacetoxysilane, and methyltris(N , N-dimethylamino)silane, aminoxysilanes such as methyltris(N,N-diethylaminoxy)silane, and ketooxime silanes such as methyltris(ethylmethylketoxime)silane. It may be a partial hydrolyzate of one or more organosilanes. Note that if the amount of organopolysiloxane or organosilane used is less than 0.5 parts by weight relative to the ioo parts by weight of component (a) described above, curability will be poor and the resulting cured film will also have weak strength. If the amount exceeds 0.5 to 20 parts by weight, the resulting film will become brittle, so the amount is preferably in the range of 0.5 to 20 parts by weight.

The curing accelerator as component (2) constituting this condensation reaction type silicone composition may also be a conventionally known curing accelerator, such as dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dioctoate, etc. Organotin compounds such as dilaurate, iron octoate,
Examples include metal salts of organic acids such as manganese octoate and tin octoate. In addition, the amount added may be a catalytic amount, but since this is an amount sufficient to form a cured film through the condensation reaction of components (a) and (b), 100% of the weight of component (a) is added. 0°1~1 for part
It may be 0 parts by weight.

The releasable silicone composition of the present invention is made by adding non-aqueous colloidal silica to the above-mentioned known addition reaction type or condensation reaction type releasable silicone composition. Fine powder is mixed with toluene, xylene, and further with n-butanol,
These silicic anhydride particles are dispersed in a mixture of isopropyl alcohol and have an average particle diameter of 1 μm.
If the average particle diameter exceeds 1 μm, the dispersibility becomes poor and the smoothness of the cured film made from the composition to which it is added is impaired, and the transparency also decreases. is preferably 0.1 μm or less. The amount of colloidal silica added is less than 0.1 part by weight based on 100 parts by weight of organopolysiloxane as the first component of the addition reaction silicone composition and component (a) of the condensation reaction silicone composition. However, if it exceeds 10 parts by weight, the adhesion of the composition to the substrate and the residual adhesion rate will decrease.
-10 parts by weight, with a preferred range of 0.5 to 5 parts by weight.

The release silicone composition of the present invention may contain the above-mentioned addition reaction type silicone compositions in predetermined amounts of the first to fourth components or the condensation reaction type silicone compositions (a) to (d).
It can be obtained by blending predetermined amounts of the components and mixing them uniformly, but this method involves uniformly mixing the first to third components or components (A) to (A) in advance, and then adding the fourth component to this.
It is desirable to add the component or (:) component. Note that paints, pigments, ultraviolet absorbers, reaction retarders, etc. may optionally be added to this composition depending on the purpose and use.

The release silicone composition of the present invention may be used as it is, but if necessary, it may be treated with toluene, xylene, methyl ethyl ketone, ethyl acetate, hexane, heptane, etc. The substrate may be treated with this composition, which may be dispersed or dissolved in an organic solvent, by applying it to the surface of the substrate using a known coating machine such as a roll coater, gravure coater, or bar coater. This coating film can then be cured by heating above 80°C or by irradiating it with ultraviolet light for a short period of time, and the cured film thus obtained exhibits excellent release properties and is dry-touch. It also has excellent anti-blocking properties, so paper and plastic films treated with this composition that have mold releasability have good productivity and have good slipperiness when processed with adhesives, so they have excellent processability. It becomes a mold release base material.

[Example] Next, examples of the present invention will be given, in which parts are parts by weight, and viscosity is a value measured at 25 ° C.
Peeling resistance, residual adhesion rate, blocking property,
The slip properties and adhesion properties are measured and tested as shown below.

[Peeling resistance] A predetermined amount of the composition is applied to the surface of a thin film or sheet-like base material, and the composition is heated in a hot air dryer at a predetermined temperature for a predetermined period of time to form a cured film. Acrylic solvent-based adhesive Olipine BPS-8170 [product name manufactured by Toyo Ink Manufacturing Co., Ltd.] or acrylic emulsion-based adhesive Olipine BPW-311011 (product name manufactured by the same company), or rubber-based solvent-based adhesive Olipine B
PS-2411 (trade name, manufactured by the same company) was applied and heat treated at IOOO°C for 3 minutes.

Next, a laminated paper with a weight of 64 g/m2 was attached to this treated surface, and aged at room temperature for 20 hours.The aged sample was cut into 5co+ width and peeled at a peeling speed of 300 mm at an angle of 180° using a tensile tester. The bonded paper was pulled at a rate of 1/min and the force (g) required to peel it off was measured.

[Residual adhesion rate] After forming a cured film of the composition on the surface of the sheet-like base material in the same manner as in the case of peel resistance, polyester Cheeve Lumirror 31B [Nitto Electric Industries ■ Surface product name] was laminated on the surface. , 70℃ with a load of 20g/cm''
After heat treatment for 20 hours, the tape was removed and attached to a stainless steel plate.

Next, this treated tape was peeled off from the stainless steel plate at an angle of 180” at a peeling speed of 30011 Im/min, and the force (g) required for peeling was measured. Measure the force (g) and calculate the force (g) required to peel this untreated standard tape.
) expressed as a percentage.

[Blocking property] A cured film was formed on the surface of the base material in the same manner as in the case of peel resistance, and the cured film surfaces were overlapped and applied at 100 kg/cm.
A load of 2 was applied and treated at room temperature for 20 hours, and then a 5 cm
Measure the force (g) required to cut it widthwise and peel it off.
This was defined as blocking property.

[Slip Property] A cured film was formed on the surface of the base material in the same manner as in the case of peel resistance, and the dynamic coefficient of friction between the cured film surface and the SBR rubber surface was measured, and this was defined as slip property.

[Adhesion] A cured film was formed on the surface of the base material in the same manner as in the case of peel resistance, and the surface of the cured film was rubbed several times with a fingertip to check whether the film came off and the adhesion.

0: Good adhesion, X: Poor adhesion Example 1 Both ends of the molecule are blocked with vinyldimethylsilyl groups, and 97.8 mol% of the total organic groups are methyl groups, and 0.9 mol% is Phenyl group, 1.3 mol% is vinyl group, 30% by weight
To 30 parts of organopolysiloxane raw rubber whose toluene solution has a viscosity of 10.000 cps, both ends of the molecular chain are capped with trimethylsilyl groups and contains 1.6 mol/sao g of 5t) 1 group and has a viscosity of 25 cps. Organopolysiloxane composition I was prepared by adding 0.7 parts of a methylhydrodiene polysiloxane agent and dissolving these in 68 parts of toluene, and then adding ultrafine powdered silicic anhydride to 110 g of this composition in butanol-xylene. After adding 0.1 g of colloidal silica (solid content 30%) dispersed with silica and diluting with 50 g of toluene, platinum vinyl siloxane complex 0, I K (containing 0.5% platinum) was added to form a release silicone composition. (hereinafter abbreviated as treatment liquid A) was prepared.

Next, this treatment liquid A was applied to an OPP film with a thickness of 40 μm using a wire doctor #8, and heat treated at 120°C for 20 seconds using a hot air circulation dryer to obtain a dry amount of 0.3 g/ After forming a cured film of a', the peel resistance, residual adhesion rate, blocking property, slipperiness, and adhesion of this film were examined, and the results shown in Table 1 below were obtained. .

Examples 2 to 4 The amount of colloidal silica added in Example 1 was changed to 0.3
Example 1 except that g, 0.5 g + 1.1 g
After treating in the same manner as above to prepare treatment solutions B, C, and D as release silicone compositions, the treatment solutions were used in the same manner as in Example 1 to form a cured film, and the physical properties thereof were examined. However, the results shown in Table 1 below were obtained.

Comparative Examples 1 to 3 Organopolysiloxane composition 11 obtained in Example 1
After diluting 0 g with 50 g of toluene, 0.1 g of a platinum vinyl siloxane complex (containing 0.5% platinum) was added thereto to prepare a treatment liquid E as a release silicone composition (Comparative Example 1).

Further, instead of the colloidal silica used in Example 1, fumed silica Aerosil 200 [trade name manufactured by Nippon Aerosil ■] 0.1 g or spherical silicone powder KMP-590 [product name manufactured by Shin-Etsu Chemical ■] 0.1 g.
A treatment liquid F (comparative example 2) and a treatment liquid G (comparative example 3) as release silicone compositions were prepared in the same manner as in Example 1 except that 1 g was added.

Next, using these treatment solutions E, F, and G, a cured film was prepared in the same manner as in Example 1, and the physical properties of these were examined, and the results shown in Table 1 below were obtained. Ta.

From this result, the addition of colloidal silica reduced the sliminess characteristic of silicone in the films treated with treatment solutions A-D of Examples 1 to 4, and improved blocking properties that affect peel resistance, residual adhesion, etc. Even if these treated films are stacked, they do not become plate-like and can be easily peeled off one by one, but with processing agents E to G of Comparative Examples 1 to 3, they become plate-like and only one sheet can be removed. It was confirmed that it took a lot of force to peel them off one by one, but it was difficult to stack them neatly together with the kudzu.

Example 5. Comparative Example 4 30 parts of polydimethylpolysiloxane with a degree of polymerization of 5,000, in which both ends of the molecular chain were blocked with dimethylhydroxysilyl groups, both ends of the molecular chain were blocked with trimethylsilyl groups, and Mi-SiH groups were added to the chain. 1. Colloidal silica (solid content 30%) consisting of ultrafine silicic anhydride dispersed in butanol-xylene and 1 part of methylhydrodiene polysiloxane having a viscosity of 25 cps and having 7100 g of 6 moles.
10 g of this composition was diluted with 50 g of toluene, and 1 g of dibutyltin diacetate was added to prepare a treatment solution H as a release silicone composition. made.

For comparison, a treatment liquid I as a release silicone composition was prepared in the same manner as above except that colloidal silica was not added.

Next, these treatment solutions H and I were applied to a polyethylene terephthalate film with a thickness of 50 μm using a wire doctor #8, and heat-treated at 140° C. for 30 seconds using a hot air circulation dryer to obtain a dry amount of 0.3 g. /+n' After forming a cured film, the physical properties of this film were examined, and the results shown in Table 2 below were obtained.

Example 6. Comparative Example 5 4 parts of a sensitizer (4-isopropyl)phenyl-1 to hydroxyisopropyl ketone was added to the processing solution A prepared in Example 1 and the processing solution E prepared in Comparative Example 1 to prepare processing solutions J and K. These were coated on a 50 μm thick polyethylene film using a wire doctor #8, the solvent was removed by air drying, and then an 80 W/cm ultraviolet lamp was placed 8 cm above the film surface and ultraviolet rays were irradiated for 3 seconds. When the physical properties of the resulting cured film were examined, the results shown in Table 3 below were obtained.

Claims (1)

[Claims] 1,1) Organopolysiloxane 100 having at least two alkenyl groups bonded to a silicon atom in one molecule
parts by weight, 2) 0.2 to 50 parts by weight of organohydrodiene polysiloxane having at least three hydrogen atoms bonded to silicon atoms in one molecule, 3) 0.1 to 10 parts by weight of non-aqueous colloidal silica, 4
) A release silicone composition comprising a catalytic amount of a platinum-based compound. 2. a) 100 parts by weight of an organopolysiloxane having at least two hydroxyl groups in one molecule bonded to a silicon atom; b) an organopolysiloxane having at least two hydrolyzable groups in one molecule bonded to a silicon atom; 1. A release silicone composition comprising: 0.5 to 20 parts by weight of polysiloxane or organosilane; iii) 0.1 to 10 parts by weight of non-aqueous colloidal silica; and d) a catalytic amount of a curing accelerator. 3. Paper and plastics coated with the release silicone composition according to claim 1 or 2.