JPH04359963A - Silicone release agent composition - Google Patents

Abstract

PURPOSE:To improve release properties, curability, and silicone-migration characteristics of an addition reaction type silicone release agent. CONSTITUTION:An organopolysiloxane having molecular ends blocked by trialkenylsiloxy groups, alkenyl groups in an amt. of 0.2 mol% or lower based on all org. groups, and a viscosity at 25 deg.C of 100,000 cP or higher, an organohydrogenpolysiloxane having at least two hydrogen atoms directly attached to silicon atoms, and a platinum catalyst are compounded to give an addition reaction type silicone release agent compsn. By using the compsn. alone, an article such as release paper for a double-coated tape is produced industrially advantageously.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention provides a cured film that has excellent curability, has a high peeling force dependence on peeling speed when formed on release paper, and has excellent silicone transferability. The present invention relates to an addition-type silicone release agent composition.

0002

[Prior art and problems to be solved by the invention] Conventionally,
In order to prevent adhesion and sticking between adhesive sheets and base materials such as paper, processed paper, and plastic films, a hardened film of a silicone composition is formed on the surface of the base material to improve releasability. is being granted.

In this case, the method for forming a silicone film on the substrate surface is as follows: (1) using a platinum-based compound as a catalyst;
(2) A method in which an organopolysiloxane containing an aliphatic unsaturated group and an organohydrogenpolysiloxane are subjected to an addition reaction to form a releasable film; (2) an organic acid metal salt catalyst such as an organotin compound is used to A method of forming a releasable film by subjecting polysiloxane to a condensation reaction is known. The silicone compositions used in these methods are all called heat-cure types that form a film by heating, and depending on their properties, they can be dissolved in an organic solvent such as toluene or emulsified. It is classified into emulsion type and solvent-free type consisting only of silicone.

Furthermore, from the viewpoint of productivity, there is currently a tendency for addition reaction type silicone compositions, which have a fast curing rate, to be used more often as release agents.

However, when used as a release agent, such as a condensation reaction type silicone composition, when formed on a release paper or the like, it has excellent release properties such as a large difference in release force between low-speed peeling and high-speed peeling. It is desirable to use a material that provides a hardened film, but
Generally, addition reaction type silicone compositions do not have satisfactory release properties of their cured films as described below. In other words, condensation reaction type silicone compositions have a substituent involved in the reaction only at the end of the base siloxane, so the cured film is relatively soft, and when formed on release paper etc., it can be peeled off at low speed and at high speed. The difference in peeling force during peeling is large, and the peeling force is highly dependent on the peeling speed. On the other hand, addition reaction type silicone compositions that have functional groups such as vinyl groups only at the molecular chain ends have a high viscosity, for example 100,000 cp (centipoise) or more, and are hardenable In addition, when the viscosity is low and it is less than 100,000 cp, the curing property is good, but when the resulting cured film is formed on release paper etc., there is a problem that the dependence of the peeling force on the peeling rate is small. . In addition, addition reaction type silicone compositions having a certain amount or more of functional groups at the molecular chain ends and side chains of the base siloxane have excellent curability, but the peeling speed of the resulting cured film is There is a phenomenon of low dependence.

[0006] Therefore, it is difficult to use only the addition reaction type as a silicone release agent in terms of productivity and quality. Therefore, it is difficult to use both the condensation reaction type and the addition reaction type. The current situation is that there are many. However, in this case, if the condensation reaction type silicone composition is not thoroughly washed after use, the condensation type catalyst, such as Sn, becomes a catalyst poison and inhibits the addition reaction of the addition reaction type silicone composition. This easily occurs, making cleaning and other steps cumbersome, which is very disadvantageous industrially. Therefore, it has been desired to develop an addition reaction type silicone release agent composition that can provide a cured film with excellent properties such as release properties, which would enable the unified use of only the addition reaction type.

[0007] The present invention has been made in view of the above circumstances.
Addition reaction type that not only has good curability, but also has excellent release properties when formed on release paper, etc., with a large dependence of release force on release rate, and also provides a cured film with excellent silicone transferability. An object of the present invention is to provide a silicone release agent composition.

[0008]

[Means and effects for solving the problem] As a result of intensive studies to achieve the above object, the inventors of the present invention have found that (a) the molecular chain terminal is blocked with a trialkenylsiloxy group, and the alkenyl group in all the organic groups is is 0.2 mol% or less, and
An organopolysiloxane with a viscosity of 100,000 centipoise or more at 25°C, (b) an organohydrogenpolysiloxane in which at least two hydrogen atoms are bonded to silicon atoms in one molecule, and (c) a platinum group catalyst. The addition reaction type silicone release agent composition blended with the above has a faster curing speed and excellent curability than conventional condensation reaction type silicone compositions. In the case of a cured film, the peeling force is highly dependent on the peeling speed, and the difference in peeling force between low-speed peeling and high-speed peeling is large, resulting in excellent peeling properties.Moreover, the cured film has significantly improved silicone transferability. I found that it gives Furthermore, by using this silicone release agent composition, it is possible to use only addition reaction type silicone compositions as a release agent, and therefore it is possible to use only addition reaction type silicone compositions. It is known that problems such as addition reaction inhibition caused by condensation reaction catalysts when used in combination can be prevented, and processes such as cleaning can be significantly shortened, and release papers such as double-sided tapes can be manufactured industrially advantageously. However, the present invention has been completed.

[0009] Therefore, the present invention provides (a) the molecular chain terminal is blocked with a trialkenylsiloxy group, the alkenyl group in all organic groups is 0.2 mol% or less, and the viscosity at 25°C is 100,000 mol%. A silicone release agent composition containing an organopolysiloxane with a centipoise or higher, (b) an organohydrogenpolysiloxane in which at least two hydrogen atoms are bonded to silicon atoms in one molecule, and (c) a platinum group catalyst. provide something.

[0010] The present invention will be explained in more detail below. Component (a), which is the main component of the silicone release agent composition of the present invention, has molecular chain terminals blocked with trialkenylsiloxy groups and all It is an organopolysiloxane in which the amount of alkenyl groups in the organic group is 0.2 mol% or less, preferably 0.05 to 0.15 mol%. This organopolysiloxane has a lower amount of alkenyl groups in the composition of the present invention than ordinary addition-type silicone release agents, so it requires three alkenyl groups at the end of the molecular chain per silicon atom.
When the number of alkenyl groups is 1 or 2, the curing speed and silicone transferability cannot be improved. Furthermore, if the amount of alkenyl groups in the total organic groups exceeds 0.2 mol%, the desired release properties cannot be obtained.

[0011] Examples of the alkenyl group in the organopolysiloxane include vinyl groups and allyl groups, with vinyl groups being particularly preferred. Organic groups other than alkenyl groups bonded to silicon atoms include, for example, alkyl groups such as methyl, ethyl, and propyl groups, aryl groups such as phenyl and tolyl groups, and furthermore, organic groups bonded to these carbon atoms. Examples include monovalent hydrocarbon groups in which part or all of the hydrogen atoms are substituted with halogen atoms, cyano groups, etc. In addition, it is particularly preferable that the organic groups other than the alkenyl group bonded to the silicon atom are methyl groups in an amount of 50 mol% or more based on the total organic groups.

The organopolysiloxane is preferably substantially linear, but may be partially branched, and further has a viscosity at 25° C. of 100,000 cp or more, preferably 1,000,000 cp or more. , less than 100,000 cp, the alkenyl group content increases and the desired release properties cannot be obtained.

Next, the organohydrogenpolysiloxane (component (b)) to be blended into the composition of the present invention has at least two, preferably three or more hydrogen atoms bonded to silicon atoms in one molecule. The presence of hydrogen atoms allows it to act as a crosslinking agent. In addition, in the present invention, the SiH group in the molecule of this organohydrogenpolysiloxane is added to the alkenyl group bonded to the silicon atom of the organopolysiloxane of the component (a),
This forms a cured film.

Further, the organic group bonded to the silicon atom of the organohydrogenpolysiloxane is not particularly limited and may be various organic groups, but generally 90 mol% or more of the total organic groups are methyl groups. It is preferable that Specifically, such organohydrogenpolysiloxanes include (CH3)HSiO units, HSiO1.
5 units, (CH3)2SiO units, (CH3)3SiO
Examples include polymers or copolymers consisting of 0.5 units, and these may be linear, branched, or cyclic.

The organohydrogenpolysiloxane preferably has a viscosity of 10 to 500 cp, particularly 15 to 200 cp at 25°C.

In the present invention, the amount of organohydrogenpolysiloxane as component (b) described above is preferably adjusted depending on the amount of alkenyl groups contained in the organopolysiloxane as component (i). In terms of film performance and peeling performance, component (a) 100 parts (parts by weight,
(the same applies hereinafter)), it is preferably in the range of 0.3 to 15 parts, particularly 0.5 to 5 parts.

Furthermore, in the present invention, in order to effectively advance the addition curing reaction, a platinum group catalyst conventionally known as this type of addition reaction catalyst is used as component (iii). Such platinum group catalysts include, for example, platinum-based, palladium-based, rhodium-based catalysts, etc., but platinum-based catalysts are particularly preferred, and specific examples include chloroplatinic acid, alcoholic solutions of chloroplatinic acid, and Examples include aldehyde solutions, complexes of chloroplatinic acid and various olefins, and vinyl siloxanes.

The amount of the platinum group catalyst to be added may be a catalytic amount, but from the economic standpoint as well as obtaining a good cured film,
(a) 1 to 1 platinum group metal amount per 100 parts of the component
It is desirable to set it as the range of 000 ppm.

In addition to the above-mentioned components, other optional components may be added to the composition of the present invention, such as various organic nitrogen compounds, organic phosphorus compounds, acetylene, etc., for the purpose of suppressing the catalytic activity of platinum group metal compounds. If necessary, an activity inhibitor such as a type compound, an oxime compound, an organic chloro compound, and a silicone resin may be added for the purpose of controlling the peeling force. The amount of optional ingredients added is as follows:
It can be used in a normal amount within a range that does not impede the effects of the present invention.

The silicone release agent composition of the present invention can be obtained by blending the above-mentioned components (a) to (c), as well as predetermined amounts of optional components.
It is preferable that component (c) is added after components (a), (b) and optional components are uniformly mixed in advance. In addition, each component may be used alone or in combination of two or more types. In addition, each component can be added to toluene, xylene,
It may also be prepared by dissolving it in an organic solvent such as n-hexane.

The silicone release agent composition prepared in this manner is applied to a base material such as paper or a plastic film, and then heated and cured by a conventional method to form a cured film, thereby forming a release paper or the like. can be manufactured.

[0022]

Effects of the Invention The silicone release agent composition of the present invention has a fast curing speed and excellent curability, and when formed on release paper, etc., the peeling force is highly dependent on the peeling speed, and it is difficult to peel off at low speed. It has excellent peeling properties with a large difference in peeling force between time and high speed peeling, and also provides a cured film with excellent silicone transfer properties.For example, it is used as a release paper for the heavy side of double-sided tape. It can be suitably used as such. Furthermore, according to the present invention, it is possible to use only an addition reaction type silicone composition as a silicone release agent, and it is possible to use both a condensation reaction type and an addition reaction type silicone composition. It is possible to prevent troubles such as addition reaction inhibition caused by condensation reaction type catalysts during the process, and the steps such as washing can be significantly shortened, which is very advantageous industrially.

[0023]

[Examples] The present invention will be specifically explained below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. Note that all parts in each example are parts by weight, and the viscosity is the value at 25°C.

Further, the curing speed, peeling force, residual adhesion rate, and silicone transferability of the silicone composition were measured by the following methods. Curing speed: The silicone composition is cured into a thin film or sheet.
Apply a predetermined amount to the surface of a tab-shaped base material, heat it in a hot air dryer at a predetermined temperature, and rub the cured film formed several times with your fingers.
The time it took to reach a state without clouding or falling off was measured. Peeling force: After applying a predetermined amount of the silicone composition to the surface of a thin film or sheet-like base material and heating it in a hot air dryer at a predetermined temperature to form a cured film, the surface of this cured film is Acrylic solvent-based adhesive Olivine BPS-512
7 (manufactured by Toyo Ink Mfg. Co., Ltd.) or an acrylic emulsion type adhesive Olivine BPW-311OH (manufactured by Toyo Ink Mfg. Co., Ltd.) was applied and heat-treated at 100° C. for 3 minutes. Next, high-quality paper with a basis weight of 64 g/m2 was attached to this treated surface, and after aging at 25°C for 20 hours, the sample was cut into 5 cm wide pieces and tested using a tensile tester.
Peeling speed 0.3 m/min, 60 m/min at 0°C angle
The force required to stick the paper together in minutes, pull the paper, and peel it off (
g) was measured. Residual adhesion rate: Polyester tape (trade name: Lumira-31B, manufactured by Nitto Denko Corporation) was applied to the surface of the cured film of the silicone composition formed on the surface of the base material in the same manner as in the case of peel force measurement. After pasting together and heat aging at 70° C. for 20 hours under a load of 20 g/cm 2 , the tape was removed and the material was pasted onto a stainless steel plate. Next, this tape was peeled off from the stainless steel plate at an angle of 180 DEG C. at a peeling speed of 0.3 m/min, and the force (g) required for peeling was measured. Also, the force (g) required to peel off the untreated tape that has not been bonded with a silicone hardened film from the stainless steel plate.
were measured, and the ratio was calculated and expressed as a percentage. Silicone transferability: After forming a cured film of the silicone composition on the surface of the base material in the same manner as in the case of peel force measurement, a 25 μm PET film was laminated on the surface and the film was applied at 10 kg/cm2 at 25°C. Perform crimping process for 60 minutes with
Measure the Si count on the silicone crimped surface of the PET film after treatment using an X-ray spectrometer (X-ray method), and check for repellency with an oil-based marker (magic method).
was evaluated.

[Example 1] Component (a) was a dimethylpolysiloxane whose molecular chain terminals were blocked with trivinylsiloxy groups, contained 0.11 mol% of methylvinylsiloxane units, and had a 30% toluene dissolution viscosity of 8000 cp. The amount of vinyl groups in all organic groups is 0.
12 mol%) 100 parts, component (b) 1.5 parts of methylhydrogenpolysiloxane having a viscosity of 150 cp, the molecular chain end of which is capped with a trimethylsiloxy group and containing 30 mol% of dimethylsiloxane units, and the following formula (2): Three parts of a silicon compound having an acetylenically unsaturated group as shown below are mixed and dissolved uniformly in toluene so that the active ingredient is 30%, and then a chain of platinum and vinyl siloxane is added as component (c). 200 ppm of platinum in the body
A silicone composition (1) was obtained.

[0026]

[Chemical formula 1]

[Example 2] Component (a) is a dimethylpolysiloxane whose molecular chain terminals are blocked with trivinylsiloxy groups and whose dissolution viscosity in 30% toluene is 5,000 cp (the amount of vinyl groups in all organic groups is 0.
Silico was prepared in the same manner as in Example 1, except that 100 parts of 06 mol%) and 1.0 part of methylhydrogenpolysiloxane with a viscosity of 20 cp whose molecular chain ends were blocked with trimethylsiloxy groups were used as component (b). -N composition (2)
I got it.

[Comparative Example 1] 100 parts of dimethylpolysiloxane whose molecular chain terminals are blocked with dimethyl hydroxysiloxy groups and whose dissolution viscosity in 30% toluene is 10,000 cp;
1. Methyl hydrogen polysiloxane with a viscosity of 20 cp and whose molecular chain ends are blocked with trimethylsiloxy groups.
After uniformly dissolving using toluene so that the active ingredient becomes 30%, an organic tin compound is added thereto to make the silicone composition 0.5% in terms of tin. (3) was obtained.

[Comparative Example 2] As component (a), the molecular chain terminal is blocked with a dimethylvinylsiloxy group, and the dissolution viscosity in 30% toluene is 5000 cp.
A silicone composition (4) was obtained in the same manner as in Example 2 except that dimethylpolysiloxane was used.

[Comparative Example 3] Component (A) was a dimethylpolysiloxane whose molecular chain terminals were blocked with trivinylsiloxy groups, contained 0.38 mol% of methylvinylsiloxane units, and had a 30% toluene dissolution viscosity of 5000 cp. The amount of vinyl groups in all organic groups is 0.
A silicone composition (25 mol%) was prepared in the same manner as in Example 1, except that the amount of component (B) was 2.2 parts.
5) was obtained.

Next, the obtained silicone compositions (1) to
The amount of (5) applied to polyethylene laminated paper was 0.8g.
/m2, and the curing speed is 100
℃ or 140℃ for other physical properties.
The measurement was performed after curing at 0°C for 30 seconds. The above results are shown in Table 1.

[0032]

[Table 1]

From the results in Table 1, the silicone release agent compositions of the present invention (Examples 1 and 2) have superior curability compared to the condensation reaction type silicone composition (Comparative Example 1). In addition, it was confirmed that the peeling force was highly dependent on the peeling rate and that it provided a cured film with excellent silicone transferability. Also,
On the other hand, the silicone release agent compositions (Comparative Examples 2 and 3) lacking any of the essential components according to the present invention have low dependence of the peeling force of the cured film on the peeling rate, and have low silicone transferability. It was inferior to

Claims (1)

[Claims] Claim 1: (a) An organoorganic material whose molecular chain terminals are capped with trialkenylsiloxy groups, where the alkenyl group in all organic groups is 0.2 mol% or less, and whose viscosity at 25° C. is 100,000 centipoise or more. Polysiloxane, (b) organohydrogenpolysiloxane in which at least two hydrogen atoms are bonded to silicon atoms in one molecule, (c)
A silico characterized by containing a platinum group catalyst
stripping agent composition.