JP2000086893A - Pressure-sensitive adhesive composition and preparation thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive composition comprising a silicone resin component and a diorganopolysiloxane component, which works effectively even onto surfaces to which adhesion is difficult due to their small friction coefficients, and a method for producing the same. SOLUTION: This pressure-sensitive adhesive composition comprises a silicone resin component comprising R3SiO1/2 units (where R is a hydrocarbon group with a carbon number of 1-5) and SiO4/2 units, and a diorganopolysiloxane component. The diorganopolysiloxane component is chemically reacted with a part of the silicone resin component, the proportion of the free silicone resin component to all the silicone resin component being 75-90 wt.% the proportion of the diorganopolysiloxane component to 100 pts.wt. of all the silicone resin component being 40-70 pts.wt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pressure-sensitive adhesive composition using silicone and a method for producing the same.

[0002]

2. Description of the Related Art In general, a silicone-based pressure-sensitive adhesive has an operating temperature range of -65 ° C. to 260 ° C., which is much wider than other organic pressure-sensitive adhesives, and can be used even in a high-temperature, high-humidity atmosphere. Has excellent properties such that there is almost no deterioration in properties, and has excellent properties such as good adhesion to various objects such as metal, glass, paper, plastic, and silicone rubber. ing.

[0003] Conventionally, as a pressure-sensitive adhesive composition using silicone as a raw material, a product obtained by reacting a silicone resin with a silicone gum and a reaction mixture containing the reaction product as an active ingredient are known. For example, Japanese Patent Publication No. 62-58637, Japanese Patent Publication No. 5-605
No. 07 gazette. However, in such a conventional silicone pressure-sensitive adhesive composition, it is generally difficult to adhere to the silicone pressure-sensitive adhesive composition because the friction coefficient and surface tension of the pressure-sensitive adhesive itself are small and the number of functional groups contributing to adhesion is small. However, there is a problem that it does not have sufficiently effective adhesion and tackiness to the surface of an object made of fluorine resin or the like.

[0004]

The present invention has been studied based on the above circumstances. As a result, the pressure-sensitive adhesive composition comprising a silicone resin component and a diorganopolysiloxane component has been developed. When the organopolysiloxane component is in a specific state and the ratio of both components is in a specific range, it has been found that the adhesive has excellent adhesion and tackiness as an adhesive, and has been completed by this finding. The object of the present invention is to provide a pressure-sensitive adhesive composition that can be effectively used even on a surface where adhesion is difficult because of a small coefficient of friction and surface tension and a small number of functional groups contributing to adhesion. It is to provide a manufacturing method.

[0005]

The pressure-sensitive adhesive composition of the present invention contains R ₃ SiO _1/2 units (R represents a hydrocarbon group having 1 to 5 carbon atoms) and SiO _4/2 units. It contains a silicone resin component and a diorganopolysiloxane component, and the diorganopolysiloxane component is chemically reacted with a part of the silicone resin component, and a free silicone resin component with respect to all silicone resin components. Is 75% by weight or more and 90% by weight or less, and the ratio of the diorganopolysiloxane component is 40% by weight or more and 70% by weight or less with respect to 100% by weight of all silicone resin components.

Here, R in the silicone resin component
The molar ratio of ₃ SiO _1/2 units to SiO _4/2 units is 0.
It is preferably in the range of 3: 1 to 1.2: 1, and the diorganopolysiloxane component preferably has a degree of polymerization of 1,000 to 10,000.

Also, a method for producing the pressure-sensitive adhesive composition of the present invention.
Is R_ThreeSiO_1/2Unit (R is charcoal with 1 to 5 carbon atoms
Shows a hydride group. ) And SiO_4/2Silico with units
Resin resin and one molecule of hydroxyl group bonded to silicon atom
And a diorganopolysiloxane raw material having at least one
The reaction mixture obtained by reacting in the presence of a catalyst is added with R_Three
SiO_1/2Unit (R is a hydrocarbon group having 1 to 5 carbon atoms)
Is shown. ) And SiO _4/2Silicone cash register including unit
The pressure-sensitive adhesive composition is produced by adding
It is characterized by that.

Here, the silicone resin raw material is characterized in that the average structure is substantially represented by the general formula (A).

[0009]

## STR2 ## formula _{^{(A) [R 1 3 SiO}} 1/2] a [R 2 SiO 3/2] b [SiO 4/2] c (R 1 is an alkyl group having 1 to 5 carbon atoms, R ² Represents a hydroxyl group or an alkoxy group having 1 to 5 carbon atoms, a, b and c
Is a positive number and the value of [a / (a + b + c)] is 0.05 to
0.7, the value of [b / (a + b + c)] is 0.01 to 0.1.
5. The value of [a + b + c] is 7 to 500. All or most of the [R ² SiO _3/2 ] units in this structure are converted to [SiO _4/2 ] units by a hydrolysis-condensation reaction in the reaction system.

[0010]

The pressure-sensitive adhesive composition of the present invention comprises a silicone resin component and a diorganopolysiloxane component, and both components are in a specific state and the composition ratio is in a specific range. Demonstrate excellent adhesion and tackiness. Further, according to the production method of the present invention, the above-mentioned pressure-sensitive adhesive composition can be produced reliably and easily.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The pressure-sensitive adhesive composition of the present invention contains a silicone resin component and a diorganopolysiloxane component, and the silicone resin component contains a part thereof in a state of being chemically reacted with the diorganopolysiloxane component. And
The remaining part is contained in a free state not reacted with the diorganopolysiloxane component. On the other hand, the diorganopolysiloxane component is contained substantially in a state where all of the diorganopolysiloxane component is chemically reacted with a part of the silicone resin component. Here, any additive component may be included in the composition, but the content ratio of the free silicone resin component and the diorganopolysiloxane component is set to a specific range with respect to all the silicone resin components. .

The free silicone resin component is a component which has not been chemically reacted with the diorganopolysiloxane component among all the silicone resin components contained in the pressure-sensitive adhesive composition. The range is 75% by weight or more and 90% by weight or less based on all the silicone resin components. If the content of the free silicone resin component is too small, effective tackiness cannot be obtained.On the other hand, if the content is too large, the adhesion becomes small and sufficient tackiness cannot be obtained. Not preferred.

The diorganopolysiloxane component is contained in a state of being chemically reacted with the silicone resin component, and its content is in the range of 40 to 70 parts by weight based on 100 parts by weight of all silicone resin components. It is said. Here, when the content ratio of the diorganopolysiloxane component is too small, the adhesion becomes extremely small, while
If the content is too large, it is not preferable because effective tackiness cannot be obtained.

The pressure-sensitive adhesive composition of the present invention as described above is produced, for example, by the following method. In this production method, a silicone resin raw material to be charged into a reaction system, a silicone resin for mixing to be added later, and a diorganopolysiloxane raw material having at least one hydroxyl group bonded to a silicon atom in one molecule are prepared. . First, in a first step, a silicone resin raw material and a diorganopolysiloxane raw material are subjected to a reaction treatment to obtain a reaction mixture. In a second step, a silicone resin for mixing is added to the reaction mixture. A pressure-sensitive adhesive composition is produced.

Hereinafter, this manufacturing method will be specifically described. (1) First Step A diorganopolysiloxane raw material and a silicone resin raw material in excess of the reaction theoretical amount are subjected to a condensation reaction in an appropriate solvent in the presence of a catalyst. The product obtained by this condensation reaction includes a condensate in which the diorganopolysiloxane raw material is chemically reacted by condensing with a part of the silicone resin raw material, and a free silicone resin component which remains unreacted. Is a reaction mixture consisting of In other words, this condensation reaction results in a state in which substantially all of the diorganopolysiloxane component has been chemically reacted with the silicone resin component.

The silicone resin raw material is R ₃ SiO _1/2
A unit represented by the general formula (A), containing a unit and an SiO _4/2 unit, and containing an RSiO _3/2 unit (R represents a hydroxyl group or an alkoxy group having 1 to 5 carbon atoms). . Here, R of R ₃ SiO _1/2 unit has 1 carbon atom.
It represents a hydrocarbon group of 5 or more and includes, for example, a methyl group, an ethyl group, an isopropyl group, and a butyl group, and a methyl group is particularly preferable. Further, this silicone resin raw material is hydrolyzed and condensed with a silanol group or an alkoxy group in a reaction system to form R ₃ SiO _1/2 unit and SiO 2.
The molar ratio with _4/2 units is in the range of 0.3: 1 to 1.2: 1. Here, when R in R ₃ SiO _1/2 unit is a hydrocarbon group having more than 5 carbon atoms, the curability of the composition is reduced, and as a result, effective tackiness cannot be obtained and stickiness is caused. And R ₃ SiO
_{If the} molar ratio of the _1/2 unit to the SiO _4/2 unit is too small, it becomes difficult to obtain a solvent having good solubility in the solvent, while if the molar ratio is too large, the amount of the diorganopolysiloxane material and Since reactivity becomes low, there is a possibility that good adhesiveness cannot be obtained.

Specific examples of the silicone resin raw material include an M unit (R ₃ SiO _1/2 unit) and a Q unit (SiO ₂ unit).
_And ^a D unit (R ^b SiO _2/2 unit) or a D unit (R ^b unit) within a range that does not affect the effects of the present invention. ₂ SiO _2/2 units) (R ^a and R ^{b each} represent an organic group). In addition, this MQ resin has R ^c SiO _3/2 units (R ^c is a hydroxyl group or carbon number 1 unit).
5 to 5 represent alkoxy groups. ) May be contained.

The material used as a silicone resin raw material in the present invention has a substantially average structure represented by the following general formula (A). Such a silicone resin can be produced by a usual method.

[0019]

## STR3 ## Formula _{^{(A) [R 1 3 SiO}} 1/2] a [R 2 SiO 3/2] b [SiO 4/2] c (R 1 is an alkyl group having 1 to 5 carbon atoms, R ² Represents a hydroxyl group or an alkoxy group having 1 to 5 carbon atoms, a, b and c
Is a positive number and the value of [a / (a + b + c)] is 0.05 to
0.7, the value of [b / (a + b + c)] is 0.01 to 0.1.
5. The value of [a + b + c] is 7 to 500. All or most of the [R ² SiO _3/2 ] units in this structure are converted to [SiO _4/2 ] units by a hydrolysis-condensation reaction in the reaction system.

Here, when the value of [a / (a + b + c)] is excessively large, characteristics such as adhesion are undesirably reduced. If the value of [b / (a + b + c)] is too large, the reaction product tends to gel, which is not preferable. Also, [a + b
When the value of [+ c] is excessively large, the obtained pressure-sensitive adhesive composition becomes excessively hard. On the other hand, when the value is too small, sufficient tackiness cannot be obtained, which is not preferable.

As the diorganopolysiloxane raw material,
For example, dimethylpolysiloxane, diethylpolysiloxane, diphenylpolysiloxane, and the like represented by the general formula (B) can be given, and it is necessary that one molecule has at least one hydroxyl group bonded to a silicon atom, and its polymerization is required. The degree is preferably in the range of 1,000 or more and 10,000 or less. Here, when the polymerization degree is less than 1000,
Sufficient adhesion cannot be obtained, and conversely, a polymerization degree of 100
If the value is larger than 00, effective tackiness cannot be obtained and stickiness occurs, which is not preferable.

[0022]

Embedded image general formula ^{(B) [R 3 R 4} 2 SiO 1/2] [R 4 2 SiO 2/2] d [R 3 R 4 2 S
iO _1/2 ] (R ³ is a hydroxyl group or an alkoxy group having 1 to 5 carbon atoms;
⁴ each independently represents an alkyl group having 1 to 5 carbon atoms;
d is 1,000 to 10,000. )

The solvent for the condensation reaction is not particularly limited as long as it can dissolve the silicone resin raw material and the diorganopolysiloxane raw material to be used. Usually, an aromatic solvent is used. Specific examples thereof include toluene and xylene. The amount of the solvent used is preferably 50 to 200 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive composition.

Further, as a catalyst for the reaction, conventionally,
Any such known materials can be used as they are and are not particularly limited as long as the condensation reaction between the silicone resin raw material and the diorganopolysiloxane raw material proceeds.

As a specific example of this catalyst, octyl
Tin oxide (Sn (OCOC)₇H_Fifteen)_Two), Tin laurate
(Sn (OCOC₁₁H_{twenty three})_Two), Tin naphthenate (Sn
(OCOC₇H₁₃)_Two), Diethyl tin octate ((C_Two
H_Five)_TwoSn (OCOC₇H₁₃)_Two), Dibutyltin octe
((C_FourH₉)_TwoSn (OCOC₇H₁₃)_Two), Dibutyl
Tin laurate ((C_FourH₉)_TwoSn (OCOC
₁₁H_{twenty three})_Two), Diethyltin laurate ((C_TwoH_Five)_TwoSn
(OCOC₁₁H_{twenty three})_Two), Dibutyltin diacetate (C
_FourH₉) _TwoSn (OCOCH_Three)_Two) And other tin compounds
And tetrapropyl titanate (Ti (OCH_TwoCH_TwoC
H_Three)_Four), Tetrabutyl titanate (Ti (OCH_TwoCH_Two
CH_TwoCH_Three)_Four), Those represented by the formula (1), and other
Tan compounds, fatty acid lead (Pb), zinc (Zn),
Iron (Fe), zirconium (Zr), cobalt (Co)
Metal salts represented by formulas (2) to (4)
Amino group-containing compounds, potassium silanolate, etc.
I can do it.

[0026]

Embedded image

Since the amount of the catalyst varies depending on the catalytic activity, it cannot be specified unconditionally. For example, in the case of potassium silanolate, potassium ion (K
⁺ ) 0.01 to 0.5% by weight in the composition in terms of the concentration
Is preferred.

The reaction temperature in the condensation reaction between the silicone resin raw material and the diorganopolysiloxane raw material is 80 ° C.
-180 ° C, especially 120-160 ° C. When the reaction temperature is, for example, 140 ° C., the time required for the condensation reaction is usually 30 to 90 minutes.

(2) Second Step A controlled amount of the silicone resin for mixing is added to the reaction mixture obtained in the first step, and the mixture is stirred until it becomes uniform. Thereby, the intended pressure-sensitive adhesive composition of the present invention is obtained.

As the silicone resin for mixing, as long as it is used as the above-mentioned silicone resin raw material,
Any of them can be used, and may be the same or different from those used as the silicone resin raw material, but the same is preferable.

According to the above-described production method, the silicone resin raw material and the diorganopolysiloxane raw material are subjected to a condensation reaction in the first step, and the resulting reaction mixture is added alone in the second step. In this step, the amount of the silicone resin to be added can be freely adjusted, so that the free silicone resin in the finally obtained composition can be adjusted. It is easy to set the components to the desired values, so that a pressure-sensitive adhesive composition having a desired composition ratio can be easily produced.

In the first step, the amounts of the silicone resin raw material and the diorganopolysiloxane raw material used, and the reaction conditions are adjusted, whereby
In some cases, the reaction mixture has an intended composition by itself, in which case the desired pressure-sensitive adhesive composition can be obtained without going through the second step. However, in practice, in the reaction between the diorganopolysiloxane raw material and the silicone resin raw material, it is difficult to control the degree of the condensation reaction by setting the content of the unreacted silicone resin component within the specified range. It is not easy to be. Therefore,
According to the above-described method of adding a silicone resin for mixing after reacting a diorganopolysiloxane raw material with a silicone resin raw material, a pressure-sensitive adhesive composition having a target composition ratio can be reliably and easily produced. .

[0033]

Hereinafter, embodiments of the present invention will be described.
The present invention is not limited to these.

<Silicone Resin Raw Material (a-1)> In Examples 1, 3-9, and Comparative Examples 1-4,
As the silicone resin raw material charged into the reaction system and the silicone resin raw material for mixing added later, the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) represented by the following formula (C) is 3370. Some were used.

[0035]

Formula (C) [(CH ₃ ) ₃ SiO _1/2 ] _a [R ² SiO _3/2 ] _b [SiO
_4/2 ] _c (R ² is a hydroxyl group, [a + b + c] = 49, [a /
(A + b + c)] = 0.49, [b / (a + b + c)]
= 0.1 and [c / (a + b + c)] = 0.41. This silicone resin raw material is converted into (CH ₃ ) ₃ SiO _1/2 units and Si by a hydrolysis condensation reaction in a reaction system.
It is a silicone resin having a molar ratio to O _4/2 units in the range of 0.96: 1 to 1.19: 1.

<Silicone Resin Raw Material (a-2)> In Example 2, the silicone resin raw material charged into the reaction system and the silicone resin raw material for mixing added later are represented by the following formula (D). One having a weight average molecular weight in terms of polystyrene of 7,400 as measured by gel permeation chromatography (GPC) was used.

[0037]

Formula (D) [(CH ₃ ) ₃ SiO _1/2 ] _a [R ² SiO _3/2 ] _b [SiO
_4/2 ] _c (R ² is a hydroxyl group, [a + b + c] = 108, [a
/(A+b+c)]=0.45, [b / (a + b +)
c)] = 0.075, [c / (a + b + c)] = 0.4
75. This silicone resin raw material is converted into (CH ₃ ) ₃ SiO _1/2 units and Si by a hydrolysis condensation reaction in a reaction system.
The silicone resin has a molar ratio to O _4/2 units within the range of 0.81: 1-1.97: 1.

<Diorganopolysiloxane raw material (b-
1)> As the diorganopolysiloxane raw materials in Examples 1 and 2 and Examples 4 to 9 and Comparative Examples 1 to 4, the degree of polymerization was 8330, the weight average molecular weight in terms of polystyrene measured by GPC was 616200, and both ends were- Si
A dimethylpolysiloxane in which R ³ in the general formula (B) of (OH) (CH ₃ ) ₂ is a hydroxyl group and R ⁴ is a methyl group was used.

<Diorganopolysiloxane raw material (b-
2)> As the diorganopolysiloxane raw material in Example 3, the degree of polymerization was 3830, the weight average molecular weight in terms of polystyrene measured by GPC was 283400, and both ends were-
A dimethylpolysiloxane in which R ³ in the general formula (B) which is Si (OH) (CH ₃ ) ₂ is a hydroxyl group and R ⁴ is a methyl group was used.

As a first step, according to the recipe shown in Table 1, a silicone resin raw material and dimethylpolysiloxane were placed in a reaction vessel equipped with a reflux condenser, a dropping funnel and a stirrer, and xylene as a solvent and a catalyst. Is added together with potassium silanolate, and the contents in the reaction vessel are stirred to completely dissolve each raw material in xylene, and then the reaction vessel is heated on an oil bath while stirring is continued. At 140 ° C. for 90 minutes.
Thereafter, the reaction mixture was allowed to cool to room temperature while heating was stopped and stirring was continued to obtain a reaction mixture.

Except for Example 9, as a second step, the amount of silicone resin for mixing shown in Table 1 was added to the obtained reaction mixture, and the mixture was stirred until it became uniform to obtain a pressure-sensitive adhesive composition. Was. In the ninth embodiment, without going through the second stage,
The composition obtained in the first step was directly used as a pressure-sensitive adhesive composition.

Here, the amount (a ₁ ) of the silicone resin raw material before the first-stage reaction and the amount (y) of the free silicone resin produced in the first stage were measured by GPC. From these values, the amount (x) of the silicone resin component subjected to the condensation reaction, the amount (A-x) of the free silicone resin component in the silicone resin component, and the total amount (x + b) of both components subjected to the condensation reaction are calculated. Each value was calculated. These values are shown in Table 1.

[0043]

[Table 1]

For each of the pressure-sensitive adhesive compositions obtained in Examples 1 to 9 and Comparative Examples 1 to 4, the following method was used.
The adhesion and the tackiness of the coating surface were measured.

The method of preparing the sample for measuring the adhesion is as follows. A base material was a tetrafluoroethylene resin tape (trade name “Teflon tape TOMB09001” (manufactured by Nichias Corporation)) having a dimension of 300 mm in length and 125 mm in width and a thickness of 0.2 mm. The adhesive composition was applied on this base material using a baker-type applicator “NO-113” (manufactured by Nippon Cedars Service), left at room temperature for 10 minutes, and then placed in a 40 ° C. oven for 5 minutes. The solvent is volatilized by heating, whereby the film thickness becomes 1
A 00 μm cured film was formed on the substrate. Then, on this cured film, thickness 0.5mm, length 150mm, width 25m
m size aluminum plate (JIS.H.4000 <A
1050P>) is placed in a state in which the area of 75 mm in the vertical direction and 25 mm in the horizontal direction are overlapped, a heavy object with a smooth bottom is placed thereon, and heating is performed in an oven at 150 ° C. for 10 minutes in this state, whereby the cured film A sample for measuring adhesion was prepared on which an aluminum plate was adhered.

The method for preparing the tackiness measurement sample is as follows. A 50 μm-thick polyethylene terephthalate (P) having dimensions of 100 mm long and 15 mm wide
ET) Film (trade name “S100” (manufactured by Diafoil Hoechst Co., Ltd.)) as a base material, and using a baker type applicator “NO-113” (manufactured by Nippon Cedars Service) as the base material, an adhesive composition Is applied and left at room temperature for 10 minutes.
By heating for 0 minutes to cure the pressure-sensitive adhesive composition, a tackiness measurement sample having a cured film having a thickness of 100 μm formed on a substrate was produced.

The method for measuring the adhesion is JIS-Z0237.
According to "Testing method of pressure-sensitive adhesive tape and pressure-sensitive adhesive sheet". In this method, as a tensile tester, "Shimadzu Autograph AGS-5KNG" (manufactured by Shimadzu Corporation) was used, and the produced sample for measuring adhesion was fixed using a 5 kgf load cell, and the tensile speed was 300 mm. The measurement was carried out under the conditions of / g / sec, and the value obtained in a state where the base material and the aluminum plate were peeled off was expressed as the adhesion.
The measurement was performed three times for each sample, and the average value is shown in Table 3.
And the obtained average value is 1.45k which is a pass standard value.
Those showing gf / cm or more were judged as acceptable in terms of adhesion.

The tackiness was measured according to JIS-Z0237.
In accordance with the "inclined ball tack test". In this method, the inclined ball tack tester has a 100
mm with a 100 mm measuring section and a total length of 200 mm with a 100 mm measuring section at the bottom, and a slope with an inclination angle of 30 °, which is fixed on a horizontal measuring table, with the cured coating face up on the measuring section The sample for measuring tackiness was fixed, and a polyester film was stuck on the runway. A ball made of high carbon chromium bearing steel (SUJ2 specified in JIS-G4805) after wiping with toluene (maximum surface roughness Ra = 0.08, sphericity 1 and JIS-B15
Ball material of ball bearing steel grade 40 specified in No. 01) is freely rolled and dropped by the gravity from the upper end of the runway, and the behavior of the ball in the measuring section is observed. This operation was repeated in order from the ball having the larger diameter shown in Table 2, and the number (B value) of the ball having the largest diameter indicating that the ball did not move for 5 seconds or longer in the measuring section was obtained. B obtained here
The same measurement is performed again on the balls having three sizes before and after the value, and the B value is confirmed. The above measurement operations are different 3
Table 3 shows the average value obtained by using the samples for measuring the tackiness. Then, for those samples whose average value of the obtained B values satisfied the condition that the pass criterion value was 3 or less, a pass was judged in tackiness. In the case where the ball having a B value of 2 was not stopped for 5 seconds or longer in the measurement section, the value was shown as 2 (-) in Table 3, and the measurement was not performed with a ball of less than 2 (-).

[0049]

[Table 2]

In the pass / fail judgment shown in Table 3, a pass was judged when the measured values of the adhesion and the tackiness satisfied the pass standard values.

[0051]

[Table 3]

The pressure-sensitive adhesive compositions of Examples 1 to 8 have sufficient adhesion and tackiness, and it is clear that they are generally good pressure-sensitive adhesive compositions. In addition, according to Example 9, it is clear that a pressure-sensitive adhesive composition having sufficient properties can be obtained in the first step. On the other hand, the pressure-sensitive adhesive composition of Comparative Example 1 has an extremely low adhesion because the content ratio of the dimethylpolysiloxane component is too small, and the composition of Comparative Example 2 has an excessively large ratio of the dimethylpolysiloxane component. In addition, the composition of Comparative Example 3 had too much free silicone resin component, and the composition of Comparative Example 4 had too much dimethylpolysiloxane component and too little free silicone resin component. In addition, the adhesive strength was smaller than the pass standard value, and the tackiness value was considerably larger than the pass standard value, so that a pressure-sensitive adhesive composition having sufficient adhesive strength and tackiness could not be obtained.

[0053]

As described above, the pressure-sensitive adhesive composition of the present invention comprises a silicone resin component and a diorganopolysiloxane component, both of which are in a specific state, and the content of which is specified. Because it is a range,
It can be effectively used on the surface of an object made of, for example, a fluororesin, which exhibits excellent adhesion and tackiness, has a small friction coefficient, and is difficult to adhere. Further, according to the production method of the present invention, the pressure-sensitive adhesive composition having the above composition ratio can be produced reliably and easily.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J002 CP031 CP032 CP062 GT00 4J035 AA05 AB07 BA02 CA05K CA05U CA051 GA01 GB01 GB03 GB05 LA03 LB02 LB20 4J040 EK031 EK032 JB09 LA01 LA06 MA02 MA05 MA09 MA10 MA12 QA01

Claims (4)

[Claims] (1) an R ₃ SiO _1/2 unit (R represents 1 to 5 carbon atoms)
The following hydrocarbon groups are shown. ) And a silicone resin component containing SiO _4/2 units, and a diorganopolysiloxane component, wherein the diorganopolysiloxane component is chemically reacted with a part of the silicone resin component, The ratio of the free silicone resin component to the silicone resin component is 75% by weight or more and 90% by weight or less, and the ratio of the diorganopolysiloxane component is 40% by weight or more and 70% by weight or less with respect to 100% by weight of all the silicone resin components. A pressure-sensitive adhesive composition comprising: 2. R ₃ Si in a silicone resin component
The molar ratio of O _1/2 units to SiO _4/2 units is 0.3: 1
The pressure-sensitive adhesive composition according to claim 1, wherein the diorganopolysiloxane component has a degree of polymerization of 1,000 to 10,000. 3. A silicone resin raw material containing R ₃ SiO _1/2 units (R represents a hydrocarbon group having 1 to 5 carbon atoms) and SiO _4/2 units, and one hydroxyl group bonded to a silicon atom. A reaction mixture obtained by reacting a diorganopolysiloxane material having at least one in the molecule with a catalyst in the presence of a catalyst contains R ₃ SiO _1/2 units (R represents a hydrocarbon group having 1 to 5 carbon atoms. ) And a silicone resin containing SiO _4/2 units, to produce the pressure-sensitive adhesive composition according to claim 1 or 2. 4. The silicone resin raw material has a substantially average structure represented by the general formula (A).
3. The method for producing a pressure-sensitive adhesive composition according to item 1. ## STR1 general formula _{^{(A) [R 1 3 SiO}} 1/2] a [R 2 SiO 3/2] b [SiO 4/2] c (R 1 is an alkyl group having 1 to 5 carbon atoms, R ² Represents a hydroxyl group or an alkoxy group having 1 to 5 carbon atoms, a, b and c
Is a positive number and the value of [a / (a + b + c)] is 0.05 to
0.7, the value of [b / (a + b + c)] is 0.01 to 0.1.
5. The value of [a + b + c] is 7 to 500. )