JPS6011950B2 - adhesive tape - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure-sensitive adhesive tape in which the pressure-sensitive adhesive layer has excellent anchoring properties to a support and has high adhesive strength.

Conventionally, Si02 units and (CQ) were placed on a tape-shaped support.
3Si○o. An adhesive tape is known which is provided with a layer of a silicone adhesive obtained by condensing a copolymer consisting of 5 units with a highly polymerized diorganopolysiloxane whose molecular chain ends are blocked with hydroxyl groups.

This silicone adhesive has excellent adhesive strength, adhesion strength, and cohesive strength, as well as heat resistance and heat resistance, which are the inherent characteristics of silicone.
It is characterized by excellent electrical properties, low-temperature properties, and water resistance, but on the other hand, the support is made of organic fluororesin, polyimide resin, polyamideimide resin,
Those made of polyamide resin, polyester resin, etc. have the disadvantage of poor anchoring ability to the support. In other words, when such adhesive tapes are partially covered with rubber rolls, etc., and when used for various other purposes, the adhesive layer migrates to the adhesive surface, causing various problems in work, and it is difficult to roll it. Even when the tape is stored for a long time in a rolled state and then used, the adhesive layer migrates to the back of the tape, making it unable to function as an adhesive tape. For this reason, when manufacturing such adhesive tapes, there are methods in which the surface of the support is chemically treated in advance using sodium amide, naphthalene solution, potassium dichromate solution, etc., and methods in which the surface of the support is electrically treated in advance. Various improvement methods have been proposed, including methods of mechanically etching the surface (graining), and methods of undercoating the surface treated or hardened by the above-mentioned method with a primer such as carbon functional silane. .

However, even with these methods, a sufficient improvement in the anchoring property was not achieved, and the phenomenon of migration of the adhesive layer to the adhesive surface and the back surface of the tape was not eliminated. This migration phenomenon occurs particularly when the adhesive surface is made of a material such as silicone rubber. The present invention aims to provide an adhesive tape that eliminates such conventional drawbacks, and this adhesive tape has the general formula {i} (where R is a substituted or unsubstituted monovalent hydrocarbon group) , R' represents a hydroxyl group, an alkoxy group, or a substituted or unsubstituted monovalent hydrocarbon group, and n is 30 to 1
It is an integer of 0000.

However, 0.0 of the total organic groups represented by R and R'
02 to 20 mol% are alkenyl groups. ) and 30 to 7 parts by weight of a diorganopolysiloxane represented by
02 units and R′SiQ. 5 units (R' represents the same meaning as above) is 1:0.3 to 1:1.2, and has at least one hydroxyl group directly connected to an elementary atom in one molecule. An organopolysiloxane obtained by partially condensing 70 to 3 parts by weight of a copolymer, in an amount sufficient to provide 1 to 3 solid Si-day bonds per vinyl group in the component a). The present invention relates to an adhesive tape in which a layer of a silicone adhesive is formed through a treated layer of an organopolysiloxane composition comprising an organohydrodiene polysiloxane of The layer has excellent anchoring properties to the support, and has strong adhesion to the adhesive surface, and is also suitable for use after being stored in a roll for a long period of time. It has the characteristic that the layer does not migrate to the back side of the tape. The present invention will be explained in detail below.

The organopolysiloxane composition as an undercoat used in the present invention is composed of one of the above-mentioned components. First, this component [A] is represented by the general formula (1). 30 to 7 parts by weight of diorganopolysiloxane;
Si02 unit and R'3Si○o. Copolymer 7 with 5 units
It can be obtained by mixing and heating 0 to 3 parts by weight of 1 to 3 parts by weight to cause a partial condensation reaction.

R in the formula (1) represents a substituted or unsubstituted monovalent hydrocarbon group, and R' in the formula (1) and in the copolymer represents a hydroxyl group, an alkoxy group, or a substituted or unsubstituted monovalent hydrocarbon group. These substituted or unsubstituted monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl and propyl groups, alkenyl groups such as vinyl and allyl groups, aryl groups such as phenyl, and these hydrocarbon groups. Examples include groups in which a hydrogen atom condensed to a carbon atom is partially substituted with a halogen atom, a sia/group, or the like. For the diorganopolysiloxane represented by the formula (1), the value of n indicating the degree of polymerization is 30 to 10,000, preferably 10.
00 to 8,000, this is because the treatment layer as an undercoat formed by the organopolysiloxane composition consisting of the components [I] has a large cohesive force, and has a high adhesive strength and tackiness. This is to make it more powerful.

In addition, the {i} component is required to undergo an addition reaction with the organohydrogenpolysiloxane (b) component in the presence of a platinum-based catalyst to form a treated layer with excellent cohesive strength and adhesive strength. For this purpose, 0.002 to 20 mol% of the total organic groups bonded to the elementary atoms of the diorganopolysiloxane represented by the formula (1), preferably 0.1 to 5
A mole percent of alkenyl groups is required. If the amount of this alkenyl group is too small, the crosslinking density will be 4.0%, making it impossible to obtain a treated layer with excellent cohesive force.On the other hand, if it is too large, the crosslinking density will become large, making the treated layer hard and sticky. It will be inferior to As is clear from the definitions of R and R' above, the diorganopolysiloxane of formula (1) has a structure at the end of its molecular chain, such as a hydroxydimethylsilyl group, a hydroxydiphenylsilyl group, or a hydroxymethylphenylsilyl group. , a hydroxydiorganosilyl group such as a hydroxymethylvinylsilyl group or a hydroxyphenylvinylsilyl group, or a triorganosilyl group such as a trimethylsilyl group, a triphenylsilyl group, a vinyldimethylsilyl group, or a vinyldiphenylsilyl group. Furthermore, the structure in the molecular chain is not limited to one type of diorganosiloxane unit, and it may of course be a copolymer of two or more types of diorganosiloxane units. It is.

Next, the Si02 unit and the R'3Si unit are partially condensed with the diorganopolysiloxane of formula (1) above.
○o. Copolymers with R'5 units are well known to those skilled in the art, and include, for example, at least one of water glass, orthoethyl silicate, and ethyl polysilicate constituting the Si02 units, and R' Co-hydrolytic condensation with at least one silane such as trimethylchlorosilane, trimethylmethoxysilane, triphenylchlorosilane, phenyldimethylchlorosilane, phenyldimethylmethoxysilane, dimethylvinylchlorosilane, and dimethylvinylmethoxysilane that constitute the 3Si0 Misaki unit. It can be obtained by

This Si02 unit and R'3Si0o. Regarding the copolymer with 5 units, if there are too many Si02 units, the compatibility with the diorganopolysiloxane of formula (1) will be poor, making it difficult to partially condense with it, and if there is too little, the cohesive strength will be Since it is difficult to obtain a good treatment layer,
Si02 unit: R'3Si○o. The molar ratio of 5 units is 1:
A ratio of 0.3 to 1:1.2 is required.

Further, in performing a partial condensation reaction between the diorganopolysiloxane of formula (1) and the above copolymer, a diorganopolysiloxane.

If the amount of xane is too large, it will not be possible to obtain a treated layer with excellent adhesion and adhesion, while if it is too small, a treated layer with excellent cohesive force will not be obtained.
As mentioned above, this is 30% of diorganopolysiloxane.
An amount of copolymer of 70 to 3 parts by weight is required for 7 parts by weight. The organohydrogenpolysiloxane as the 'o} component is a component that undergoes a crosslinking reaction with the {i} component, and examples thereof include the following.

/a\table /b R has the same meaning as above, Me is a methyl group, a=2-4,
b = 0 to 4, where a + b = 3 to 8 R and Me have the same meaning as above, R' is a hydrogen atom or a monovalent hydrocarbon group,
p=0 to 300 Liq=0 to 3000 However, one molecule of poppy must have two or more hydrogen atoms bonded to elementary atoms.

R and R″ have the same meaning as above, c=1 or 2, d
= 2 or 3, where c + d = 4 [RSi○, . 5] unit, [(R)(H)Si○] unit, and depending on the case, [
Platinum or a platinum compound as a component of an organohydrogenpolysiloxane having a resin structure consisting of R2SiO] units is known as a catalyst for the addition reaction between an organopolysiloxane containing a pinyl group and an organohydrogenpolysiloxane. These include chloroplatinic acid, alcohol-modified chloroplatinic acid, chloroplatinic acid complex with olefin, platinum, black, alumina,
An example is one in which solid platinum is supported on a carrier such as silica.

The adhesive tape of the present invention is produced by applying the above-described organopolysiloxane composition consisting of one component to the surface of a tape-shaped support as an undercoat, and heating this coated layer as necessary. , is manufactured by forming a layer of a conventionally known silicone adhesive on this surface.

When applying the above organopolysiloxane composition, in order to make it easier to apply, it is diluted with a solvent, and in order to further strengthen the coating film, a finely powdered silica filler or the above-mentioned filler is used. Silicone-based wetting agents (surfactants) that are added for the purpose of making it easier to mix and integrate with essential ingredients, and inorganic and organic pigments and dyes that are added for the purpose of coloring, are included in this product. There is no problem as long as it does not interfere with the purpose or effect of the invention.

On the other hand, as the silicone adhesive applied to the method of the present invention, there are conventionally known silicone adhesives, such as Si02 units and (C
H3) 3Si○o. The molar ratio with 5 units is 1:0.4-1
: 30 to 70 parts by weight of English polymer of 1 and 70 to 3 parts by weight of dimethylpolysiloxane raw rubber, or one made using a material partially containing phenyl groups as this dimethylpolysiloxane raw rubber ( Special Public Service 1966
No. 5186, No. 32-5099), which includes Shin-Etsu Chemical's KR-10 as a commercial product.
1, DC-280 manufactured by Dow Corning, etc.

The tape-shaped support used in this invention is made from an organic fluorine-based polymer such as polytetrafluoroethylene, polytrifluoromonochloroethylene, or a copolymer of tetrafluoroethylene and hexafluoropropylene. Examples include glass fiber cloth tapes whose surfaces are coated with these organic fluorine-based polymers, and sheet-like products thereof.

The adhesive tape according to the present invention is obtained by first forming a treated layer of a composition consisting of one of the above-mentioned components on the surface of such a tape, and then dissolving the composition in various organic solvents on this treated layer. It is manufactured by coating a silicone adhesive coating liquid by an appropriate method to form an adhesive layer.

{The coating amount of the organopolysiloxane composition consisting of one component is at least 0.02 mm/〆, especially at least 0.2 mm/〆 on the support, and the silicone adhesive is The film thickness may be set to approximately 0.001 to 0.5 mm.

In the adhesive tape according to the present invention, the organopolysiloxane composition consisting of one component as the undercoat layer exhibits an excellent primer-like effect on the silicone adhesive layer, so that it supports the silicone adhesive layer. It has a great anchoring force on the body, and therefore has the excellent feature of not causing undesirable phenomena such as so-called "glue peeling" and "glue floating".

Another feature of conventional silicone adhesive tapes is that they are susceptible to the effects of atmospheric temperature and humidity during long-term storage, causing the adhesive to peel off, the adhesive layer to extrude, and the support and adhesive layer to peel off. However, due to the misalignment, the so-called "bamboo shoot" phenomenon tends to occur, making it difficult to store for long periods of time and making storage management extremely difficult.
The adhesive tape obtained according to the present invention has excellent adhesion of the organopolysiloxane composition to the support and excellent adhesion of the silicone adhesive to the composition, and therefore the cohesive strength of the adhesive tape as compared with that of a silicone adhesive. In addition to having excellent features such as being able to be used with adhesives that have a large surface area and not having any of the above-mentioned drawbacks, this product also exhibits extremely excellent adhesion to surfaces made of various materials. Furthermore, when peeled off after being adhered to various material surfaces for a long period of time, which is the original main objective of this invention, it exhibits an extremely excellent advantage in that no transfer of the adhesive layer is observed on the adhered surface.

Next, examples of the present invention will be given. However, the measurement conditions for each data in the following description are as follows.

〔Adhesive force〕

(Inclination) formula expressed as the maximum diameter (in inches) of a steel ball (JIS G4805 SUJ2) rolled from a run-up distance of 10 arcs on a slope with an inclination angle of 300 and stopping within the range of 10 degrees of adhesive layer. ball tack measurement method).

Measurement conditions were temperature 25±2℃ and relative humidity 65±5.
%. [Adhesive strength] SUS27CP stainless steel plate (thickness 1.2cm, medium 30cm)
Gently stick the test piece with the adhesive layer side down in the center of the test piece (length: 160 mm), and then apply a roller (approximately 6 mm thick) covered with a rubber layer weighing 2,000 ± 50 mm onto the center of the specimen. (made of metal), the test piece is crimped by making one reciprocation at a crimping speed of about 300/min.

The crimped test piece was heated at 25q0±2°C, 65°C for more than 30 minutes.
After leaving it in a constant temperature room with ±5%RH, remove the play part by 1.
It is expressed as the peeling force when the sample was folded back to 800 mm and peeled off continuously at a speed of 30 m/min. [Cohesive force] A test piece was pasted on a stainless steel plate at a height of 2 ribs and an area of the mid-sacral rib, a load of lk9 was applied, and the temperature was 25°C at 25°C, 65±5%.
The displacement distance after being left in the RH atmosphere for 30 minutes is shown.

[Transferability of the adhesive layer to the back side of the tape]

50 qts of adhesive tape rolled around a bobbin 90
After being left in a feces atmosphere at %RH for 7 days, the temperature was 25±20.
When the adhesive layer was left in an atmosphere of 0.65±5% RH for 30 minutes and then rapidly rewound at a speed corresponding to the unwinding speed of 50 to 100/min, the adhesive layer migrated to the back surface of the tape. It was determined visually whether or not floating occurred in the adhesive layer.

Reference example Coating solutions 1 to W were prepared as follows.

Coating liquid 1: Me3Si○o. 5 anchor parts of methylpolysiloxane resin consisting of a ratio of 0.7 mol of 5 units and 1 mol of Si02 units (
Parts indicate parts by weight.

(same below), 98 moles of Me2Si○ units, and (C mother = C
H) (Me) A crude rubber-like diorganopolysiloxane consisting of 2 moles of Si units and 2 moles of Si units are mixed with toluene and subjected to a partial condensation reaction at a temperature of 100 to 130 o'clock for about 6 hours to form vinyl. A 60% toluene solution of group-containing organopolysiloxane was obtained. To this toluene solution, a methylhydrodiene polyamide, which has both ends of the molecular chain blocked with trimethylsilyl groups, has an average degree of polymerization of 200, and has a hydrogen atom content of 0.5 out of 100 directly connected to the poppy element. Coating liquid 1 was prepared by adding 2% by weight of siloxane, adding chloroplatinic acid so that the amount of platinum was 1 gale, and further diluting with toluene so that the nonvolatile content was 3% by weight. Coating liquid 0: Coating liquid D was prepared by adding 10 parts of silicone adhesive KRIOI-10 (trade name of Shin-Etsu Chemical Co., Ltd.), 1.2 parts of penzoyl peroxide, and 10 parts of toluene.

Coating liquid m: Me3Si○■ unit 0.55 mol and Si02
45 parts of methylpolysiloxane resin consisting of 1 mole of Me2Si○ units and 99 moles of Me2Si○ units (CH2=CH
) (Me) 55 parts of raw rubber-like diorganopolysiloxane consisting of 1 mole of Si0 units are mixed with toluene, and the mixture is subjected to a partial condensation reaction at about 120°C for 1 hour to form a vinyl group-containing organopolysiloxane. A 60% toluene solution was obtained. For 100 parts of this toluene solution,
Me3Si○o. 5 units and Me2Si0 units and (Me)
(H) Consisting of Si0 units, with an average degree of polymerization of 360,
The content of hydrogen atoms directly connected to silicon atoms is 0 out of 100.
．． Add 4 parts of methylhydrodiene polysiloxane containing 25 parts, add chloroplatinic acid so that the amount of platinum becomes 20 parts, and further dilute with toluene so that the nonvolatile content becomes 3% by weight. A coating liquid m was prepared.

Coating liquid N: Me3Si○o. 60 parts of methylpolysiloxane resin consisting of a ratio of 0.9 mol of 5 units and 1 mol of Si02 units, Me2Si○ units, (Me) (C6 days 5) Si○ units, and (CH2=CH) (Me)Si○ A rubber-like diorganopolysiloxane consisting of units (3 pinyl groups among all organic groups)
mol%, phenyl group 1 mol%) 4 Boto was mixed with toluene, and this was subjected to a partial condensation reaction at about 110q0 for 12 hours to form a vinyl group-containing organopolysiloxane with 60
% toluene solution was obtained.

For 100 parts of this toluene solution, (Me)2(H)
Si○ 5th grade unit, (Me) (H) Sj○ unit and C64S
i0,. 5 units and Me2SiO unit, the average degree of polymerization is 50, and the content of hydrogen atoms directly bonded to elementary atoms is 0.5 out of 100. Needle sphere, organohydrodiene polysiloxane containing 2 mol% of phenyl groups among all organic groups.
A coating liquid W was prepared by adding chloroplatinic acid to the solution so that the amount of platinum was 3 parts.

Example 1 Coating solution 1 prepared in Reference Example was applied to a tape treated with sodium amide on one side of polytetrafluoroethylene with a thickness of 0.08, as well as polyester tape, polyimide tape, and glass cloth tape.
oo for 15 minutes to form a treatment layer with a thickness of 0.05, and then apply coating liquid 0 on top of this to form a 0.05-thick treatment layer.
The adhesive layer was dried for 10 minutes to form an adhesive layer of 0.035 willow thickness, and an adhesive tape was prepared.

Table 1 shows the properties of these tapes. Comparative Example 1 in Table 1 shows the case where coating liquid 1 was not used at all. From Table 1, the effects of the present invention are clear, and the resulting pressure-sensitive adhesive tapes had no transfer of the pressure-sensitive adhesive layer to the adhesive surface, and had extremely excellent workability and performance.

Table 1 ○: No migration is observed. △〃 Partial migration is observed.

×〃 Full-surface migration is observed o Example 2 The coating liquid m shown in the reference example was applied to the tape made of the material used in Example 1, and dried and cured at 150 mm for 10 minutes.
Further, coating liquid 0 was applied to form an adhesive layer, and the resulting adhesive tape was dried at 160 qo for 15 minutes. Table 2 shows the various performances of the adhesive tape.

In Comparative Example 3 in Table 2, instead of the coating liquid W, 1.2% penzoyl peroxide and 10% toluene were added to the silicone adhesive SH-4280 [trade name manufactured by Toray Silicone Co., Ltd.].
A 0% mixture was used.

Table 2 Example 3 The same tape that was opened in Example 1 was treated with coating liquid V under the same conditions as Example 1, and then coating liquid B used in Example 1 was applied on top of it. Table 3 shows the performance of adhesive tapes prepared under the same conditions as in Example 1.

In addition, Comparative Example 4 in Table 3 shows data when the adhesive layer was formed by applying only the coating liquid D without using the coating liquid V at all.

Table 3

Claims (1)

[Claims] 1. On the tape-shaped support, there is (a) a general formula ▲ mathematical formula, chemical formula, table, etc. ▼ (R in the formula is a substituted or unsubstituted monovalent hydrocarbon group, R
' represents a hydroxyl group, an alkoxy group, or a substituted or unsubstituted monovalent hydrocarbon group, and n is an integer of 30 to 10,000. However, 0.0 of the total organic groups represented by R and R'
02 to 20 mol% are alkenyl groups. ) and 30 to 70 parts by weight of diorganopolysiloxane represented by
O_2 units and R'_3SiO_0_. The molar ratio with _5 units (R' represents the same meaning as above) is 1:0.3 to 1
:1.2, and an organopolysiloxane obtained by partially condensing 70 to 30 parts by weight of a copolymer having at least one hydroxyl group directly bonded to a silicon atom in one molecule, (b)
1 to 30 S per vinyl group in the component (A)
A silicone adhesive layer is formed through a treated layer of an organopolysiloxane composition consisting of an organohydrodiene polysiloxane in an amount sufficient to provide i-H bonds, and (iii) a catalytic amount of a platinum catalyst. Adhesive tape.