JPS60190458A - Silicone composition for mold releasant - Google Patents

Abstract

PURPOSE:To provide the titled composition having high rate of cure and low peeling resistance, and resistant to the viscosity lowering of the adhesive, by compounding a specific organopolysiloxane with an organohydrogen polysiloxane and platinum or a platinum compound catalyst. CONSTITUTION:The objective composition can be prepared by compounding (A) an organopolysiloxane of formula II (R<3> is univalent hydrocarbon group; b<=3) having molecular chain terminals blocked with the organosiloxy group of formula I (R<1> is univalent aliphatic unsaturated hydrocarbon group; R<2> is univalent hydrocarbon group; a is 2 or 3) and an unsaturated group content of 0.05-15mol% with (B) the organohydrogen polysiloxane of formula III (c+d<=3) containing preferably >=3 identicalSiH bonds in a molecule and (C) platinum or a platinum compound catalyst. The molar ratio of the unsaturated group in the component A to the identicalSiH group in the component B is 0.2-2, and the amount of the component C is 0.01-0.1% based on the sum of the components A and B, in terms of platinum.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a silicone composition for mold release, and particularly to a silicone composition for mold release that has a fast curing speed, easy releasability, and hardly reduces the adhesive strength of an adhesive. It is.

Conventional method 1: In order to prevent adhesion and sticking between a base material such as paper, processed paper, or plastic and an adhesive substance, a silicone film is formed on the surface of the base material to impart mold releasability. has been carried out13, which includes organopolysiloxane containing an aliphatic unsaturated hydrocarbon group and 1Es.
Silicone compositions are commonly used in which an addition reaction is carried out with an organohydrodiene polysiloxane containing an iH bond in the presence of a platinum-based catalyst.

Conventionally known mold release silicone compositions usually have this aliphatic unsaturated group-combined organopolysiloxane whose molecular chain ends are dimethylmonovinylsiloxy groups represented by (OH=OH)(OH)232SiO-. However, this is because if the amount of vinyl groups as aliphatic unsaturated hydrocarbon groups is 1.0 molar or less, the curing speed becomes slow and the productivity of the release paper decreases. 0
If it exceeds the molar ratio, the rate of faeces will be too fast, the pot life of the composition will be shortened, the workability will be poor, and the mold releasability of the silicone film will also be poor.

It is usually in the range of 1.0 to 10.0 molar ratio, preferably 2 molar ratio or more, but the composition consisting of such an organopolysiloxane and an organohydrodiene polysiloxane has a hardening effect obtained from the composition. There is a limit to the reduction in peeling force of the film, and when this cured film is exposed to the outside air, the peeling force increases and the mold releasability deteriorates. Therefore, in order to improve the peeling force of this persimmon composition, a method is proposed that balances the content of unsaturated groups in the organopolysiloxane and the content of 581H bonds in the organohydrodiene polysiloxane. According to this method, the peeling force can be lowered, but the organopolysiloxane that did not participate in the addition reaction is eluted onto the surface of the silicone film formed by this reaction.

There are disadvantages in that the eluted silicone transfers to the adhesive layer and reduces the adhesive strength, and when the substrate after the film is formed, the eluted silicone transfers to the back side of the substrate, impairing printability.

The present invention relates to a silicone composition for mold release that solves these disadvantages, and is characterized in that: (a) the molecular chain terminal is R''R;
25in- \ R1 is the same or different aliphatic monovalent unsaturated hydrocarbon group - R2 is an unsubstituted or substituted 1-hydrogen group, a is organosiloxy represented by 2 or 3) Blocked at base. -7 An organopolysiloxane h represented by a different type of unsubstituted or substituted monovalent hydrocarbon group, b being a positive number of ≦3.

口）General formula R”H810＼R3 is c(14-c-
d Same as above +O−d is a positive number and organohydrodiene polysiloxane represented by c + d≦3).

c) Platinum or a platinum-based compound catalyst.

In other words, the present inventors have made various efforts to develop a silicone composition for mold release that has a fast curing speed, has a cured film with excellent mold release properties, and does not cause a decrease in the adhesive strength of the adhesive due to unreacted substances. As a result of investigation, it was found that if the aliphatic unsaturated group-containing organopolysiloxane constituting the addition reaction type silicone composition is capped with a siloxy group containing two or three aliphatic unsaturated groups at the molecular chain end. We have discovered that it is possible to obtain a cured film that has a faster curing speed than conventional products, has easier peelability, and has less tendency to peel heavily even when exposed to the outside air.

Due to the excellent 1lIilI type properties, the amount of organohydrodiene polysiloxane has to be particularly low, thus reducing the adhesion of the adhesive caused by unreacted organopolysiloxane and reducing the adhesion of the treated substrate. The present invention was completed by confirming that it is possible to prevent the deterioration in printability on the surface paper when an adhesive is applied and the surface paper is bonded together.

The a) component constituting the silicone composition for mold release of the present invention is represented by a monomolecular end or RR8iO-a aa, where R1 is an aliphatic unsaturated group such as a vinyl group-allyl group or an ethynyl group, R2 is a methyl group.

Alkyl groups such as ethyl group and propyl group, 7-enyl group,
Aryl groups such as tolyl groups, cycloalkyl groups such as cyclohexyl groups, and cyclomethyl groups in which part or all of the water X atoms bonded to the carbon atoms of these groups are substituted with halogen atoms, cyan groups, etc. An unsubstituted or substituted monovalent hydrocarbon group consisting of a logrovir group, a cyanmethyl group, etc., where a is 2-t! A siloxy group containing 2 or 3 aliphatic unsaturated groups, which must be 3 or 3, and includes a divinylmethylsiloxy group,
Examples include diallylmethylsiloxy groups.

This organosimixane is represented by the general formula Rb5104-b (-R is the same as above), and b is a positive number of ≦3.

This organopolysiloxane has either a straight or branched structure as long as one end of the molecule is blocked with a siloxy group having two or three unsaturated groups as described above.
Further, it may be partially cross-linked or may be a mixture thereof. If the content of unsaturated groups in this organopolysiloxane is less than 0.05 mole, the curing speed of the composition will be slow and it will become impractical, and if it is more than 15 mole%, the mold releasability of the silicone film made from this composition will deteriorate. Since it starts to decrease, 0.05
It is necessary to have a mole of ~15 mol, but preferably 0.
It is preferably in the range of 2 to 2.0%. This product has excellent mold releasability by having two or three unsaturated groups at the end of the molecular chain, but this effect becomes more pronounced as the number of unsaturated groups in the molecule decreases. It is larger, and the number of unsaturated groups at the end of the molecular chain is 3 compared to 2.
This gives the effect of faster curing speed. There are no particular restrictions on this viscosity, but if an organic solvent is used, the adhesion to the base material.

From the viewpoint of preventing repellency during coating, it is preferable that the viscosity at 25°C is 10,000 cS or more,
50-10.000o8 when no organic solvent is used
It is better to

Next, the organohydrodiene polysiloxane as a component in this composition has the above-mentioned general formula R"H
It is represented by BiO, and R3゜ a 4-c-d is an alkyl group such as a methyl group, an ethyl group-globyl group, or a butyl group, an alkenyl group such as a vinyl group or an allyl group, or an aryl group such as a phenyl group-tolyl group. , alkaryl groups such as ethylphenyl groups, cycloalkyl groups such as cyclohexyl groups, chloromethyl groups in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with halogen atoms, cyan groups, etc., trifluoro Propyl group.

The same or different unsubstituted or substituted monovalent hydrocarbon groups selected from cyanomethyl groups, etc., o and d are positive numbers, and o +
Although d≦3, this may be either a linear-branched candy-like structure or a partially cross-linked structure, or a mixture thereof. Also,
This organohydrodiene polysiloxane often has at least three silicon-bonded hydrogen atoms (ESIH) in one molecule, and the ratio of these silicon-SiH bonds to the atoms or groups bonded to silicon atoms is is preferably 0.1 to 95 moles/1/thi, preferably 30 to 80 moles. Note that the viscosity of this material does not need to be particularly limited, but it may normally be 3 to 500 cS.

These include metal platinum, metal platinum supported on carriers such as alumina and silica, chloroplatinic acid, alcohol-modified chloroplatinic acid, complexes of chloroplatinic acid and olefins, and chloroplatinic acid and olefins. Examples include complexes with unsaturated group-containing organopolysiloxanes, but these complexes include alcohols, ketones,
ether.

It is preferable to use it by dissolving it in a solvent such as a hydrocarbon.

The silicone composition for mold release of the present invention is as described above (a) 1 mouth)
It can be obtained by uniformly stirring and mixing the components (c) and (c), but the blending ratio of the components (a) and (b) is
If the molar ratio between the unsaturated loading in the component and the :SiH bond in the component is less than 0.2 or more than 2.0, the silicone component that does not participate in the addition reaction will be excessive and this curing reaction will be hindered. Therefore, it is necessary to set it in the range of 0.2 to 2.0, but if it is less than -1.0, it will not participate in the reaction. (a) The component will be eluted to the surface of the silicone film formed in this reaction. ．． This molar ratio is preferably in the range of 1.0 to 2.0 since it is eluted on the back surface of the substrate after treatment. In addition, if the amount of component c) is too small, the catalytic effect will be insufficient, and if it is too large, the cost will increase.
The content may be in the range of 0.01 to 0.1%.

Moreover, one composition of the present invention is the above-mentioned a)-portion).

C) It is composed of ingredients, but it has the purpose of extending the pot life or suppressing the catalytic activity of platinum at room temperature.
In G, known activity inhibitors such as various organic distillate compounds, organic phosphorous compounds, sulfur-containing compounds, acetylene compounds, etc. may be added, and furthermore, dimethylpolysiloxane-silicone face etc. which do not have a functional ion group may be added. may be added. In addition, this composition may be diluted with an organic solvent such as toluene-xylene, dolchloroethylene, pertetrachloroethylene, hexane, ethyl acetate, and methyl ethyl ketone before use.

The composition of the present invention described above is particularly useful for rainfall applications, such as kraft paper.

It is said that cellulose substrates such as glassine paper and polyethylene laminate paper are particularly useful for making release paper, but this can also be applied to glass, mineral fiber substrates such as asbestos, synthetic fibers such as polypropylene, polyethylene, polyethylene terephthalate, nylon, etc. It is also useful for treating inorganic surfaces such as films, sheet substrates, glass, iron, and alonium.

Next, examples of the present invention will be given. In one example, parts are parts by weight, viscosity is a value measured at 25°C, and in the examples, MS is a methyl group, Ph is a phenyl group, and (1) is a vinyl group. In addition, the film formation rate, mold releasability (peeling force), and residual adhesiveness of the adhesive (residual liquid rate) in the examples are the results of measurements by the following method.

(Film formation rate) Apply the silicone treatment bath onto the substrate at a rate of 0.8g/
n? The silicone coating on the fence was heated in a hot air circulation dryer and the silicone coating was dried to give the following properties.

(Peeling force) The silicone treatment bath coated substrate obtained above was heated to 150℃ for 30 minutes.
Heat cure for a second to make silicone-treated paper (), and then
One 18-tablet tablet was molded at 5°C, and then an acrylic solvent-based adhesive, BF2-5127 (Toyo Ink Co., Ltd. product name) was applied to the surface so that the solid content was 50 g/d.
After drying for 3 minutes, paste it on the surface of high-quality paper, press it back and forth once with rubber rolls 2 and 7, and leave it at 25°C for 1 day to make a test piece (width 5 t:m) for measuring peeling force. The peeling speed was measured using an autograph at a peeling angle of 186° and 063 m/min.

(Residual liquid rate) A commercially available kraft tape was pasted on the silicone-treated paper obtained above, and a load of 20 fl/lri was applied at 70°C.
0 hours, and in order to measure the standard adhesive force, a similar pressure bonding process was applied to a Teflon plate using craft tape, and the adhesive strength was measured according to the above method. The adhesive strength of the tape attached to the board was set as 100, and the residual bond rate of each sample was calculated.

Example 1-Comparative Example 1 Both ends of the molecular chain were blocked with trivinylsiloxy groups. Viscosity 20.00 where 0.6 molar fraction of all organic groups are vinyl groups
100 parts of 00F dimethylpolysiloxane has a viscosity of 250 with both ends of one molecular chain blocked with trivinylsiloxy groups.
An organohydrodiene polysiloxane represented by the formula P0.
5 parts (=siH/=sivi-1,0 (molar ratio))
and 1.0 part of a complex salt of chloroplatinic acid and vinylsiloxane (0.003 part in terms of platinum) were added and mixed uniformly to prepare a silicone treatment bath.

Next, this treatment bath was applied to high-quality paper laminated with polyethylene using an offset coater, and the amount of silicone applied was 0.8 g/n? Coat it so that it becomes .

A silicone film was formed by heating in a hot air circulation dryer, and the film formation time, releasability (peel force) of the silicone film thus obtained, and residual adhesiveness of the adhesive were measured. The peel force of the silicone-treated paper thus obtained was measured after the silicone-treated surface was exposed to the outside air for three periods.

A result of 0 was obtained as shown in Table 1.

In addition, for comparison, a silicone film was prepared in the same manner as above, except that the dimethylpolysiloxane mentioned above was blocked with monovinyldimethylsiloxy groups at both ends of the molecular chain, and the film formation time, releasability, and residual adhesive rate were When examining the peeling force after exposure to outside air, the results shown in Table 1 were obtained.

15- Table 1 Example 2 10 parts of dimethylpolysiloxane in Example 1
A silicone film was prepared in the same manner as in Example 1, except that it was substituted with dimethylpolysiloxane, which does not contain a vinyl group and has a viscosity of 1.500 o 8, with both ends of the molecular chain capped with trimethylsiloxy groups. When we investigated its physical properties, we found that the film formation time was 13 seconds and the peeling force was 10 g and 15 cy.
n, the residual contact ratio is 88 and 13. Almost the same results as in Example 1 were obtained.

16- Examples 3-6. Comparative Examples 3 to 6 Both ends of the molecular chain are blocked with a trivinylsiloxy group, divinylmethylsiloxy group, vinyldimethylsiloxy group, or trimethylsiloxy group, and the amount of vinyl in the total organic groups is 0.2
．． In terms of 0.4 or 1.0 moles.

The viscosity of the Shuluene solution is 13,000 cP, as shown in Table 2, so that the silicone content is 30%.1 In 100 parts of the various dimethylpolysiloxanes, both ends of one molecular chain are blocked with dimethylhydrodienesiloxy groups. The viscosity is 18, and the dimethylsiloxy group in one molecule is 15 mo/l/%.
0 t:; o of methylhydrodiene polysiloxane of P, s m Cmi 81H/di51vi = 2.0 (molar ratio)), 0.4 part (EEI i H/EESiVi
= 1.0 (% ratio)] or YCK 2.0 parts (ESi
H/Mi5iVi = 5.0 (molarization)] and 1.0 part of a complex salt of chloroplatinic acid and vinylsiloxane (0.01 parts in terms of platinum)
1,900 parts of toluene was added and uniformly dissolved in 1,900 parts of toluene to prepare a treatment bath containing 5% silicone.

Next, this treatment bath was applied to high-quality paper laminated with polyethylene using a wire bar.
/, and the film formation time, film releasability, and residual adhesion rate of the adhesive were measured in the same manner as in Example 1, and the results of 1J were shown in Table 3. Obtained.

19- Table 3 Example 7.8 Both ends of the molecular chain are blocked with trivinylsiloxy groups, (
The 1111 chain contains silicon f that does not contain a vinylsiloxy group.
15 moles of all the organic groups bonded to the JP molecules are vinyl groups. To 100 parts of dimethyl polysilo 20-xane having a viscosity of 60 o 8, 80 parts of methyl hydrodiene siloxy group, in which both ends of one molecular chain are blocked with trimethyl siloxy groups, are added.
15 parts of dimethylhydrodienebolysiquaxane containing molar ratio (ES IH/=-EiVi=1.0 (molar ratio)
] and 0.5 part of the platinum catalyst used in Example 3 (0.5 parts in terms of platinum)
．． 0.005%) and 0.3 part of acetylene alcohol as a reaction control agent.

This was treated in the same manner as in Example 3 to form a silicone film on the substrate, and its physical properties were examined, as shown in Table 4. The results were obtained.

Furthermore, as the dimethylpolysiloxane mentioned above, both ends of the molecular chain are capped with trivinylsiloxy groups,
When using dimethylpolysiloxane with a viscosity of 60 cS, which has 5 moles of methylvinylsiloxy groups in the side chain,
The physical properties are as listed in Table 4, and it was confirmed that in this case, the release force was heavy (but the film formation time was even shorter).

Table 4 Example 9 Both ends of the molecular chain were blocked with divinylmethylsiloxy groups. Of the total organic groups bonded to silicon atoms, 1.3 mole fraction are vinyl groups. To 100 parts of dimethylpolysiloxane with a viscosity of 2,000oS, 95 methylhydrodienesiloxy groups each having both ends of one molecular chain blocked with trimethylsiloxy groups was added.
1.1 parts of dimethylhydrodiene polysiloxane with moles [=SiH/=BiVi-1,0 (mo# ratio)]
, 1.0 part of the platinum-based catalyst used in Example 3 (0.01% platinum equivalent), 0.3 parts of ethylene alcohol as a reaction control agent, and both ends of the molecular chain were blocked with trimethylsiloxy groups. Add 2 parts of rubberized dimethylpolysiloxane with a viscosity of 10,000,000o8 and mix uniformly to prepare a silicone treatment bath, which is treated in the same manner as in Example 3 to form a silicone film on the substrate. When I investigated the physical properties of this product, the film formation time was 30 seconds.
The peeling force was 20g75, and the residual adhesion force was 93%.

Example 10 Both ends of the molecular chain were blocked with trivinylsiloxy groups. 70 parts of dimethylvinylsiloxane with a viscosity of 3,000 cP in which 1.5 moles of all organic groups bonded to silicon atoms are vinyl groups, (OH3)IIs'Q), It small unit S
This (OH3)3Sin, which consists of iO units, /810. is 0.90(-
a mixture with 30 parts of methyl silicone resin.

Two parts of methylhydrodiene polysiloxane with a viscosity of 25 cP (=SiH/=Biyi=1.5 (molar ratio)), both ends of the molecule are blocked with monohydrodiene dimethylsiloxy groups, chloroplatinic acid, and vinylsilxane. The slender body of 0.
Add 5 parts (0.005 part of platinum equivalent) and mix uniformly to prepare a silicone treatment bath 6).

This was treated in the same manner as in Example 3 to form a silicone film on the substrate, and the physical properties thereof were examined, and the results shown in Table 5 were obtained.

Also, for comparison, the dimethylvinylsiloxane mentioned above has a vinyl group content of 1.5 mol in which both ends of one molecular chain are blocked with monovinyldimethylsiloxy groups, and a viscosity of 3.0
A silicone treatment bath was prepared in the same manner as above except that 70 parts of 00cP dimethylvinylsiloxane was used, and the physical properties of the resulting silicone film were examined.
The results shown in Table 5 were obtained.

100 parts of dimethylvinylsiloxane shown in Example 11 in Table 5 and having a viscosity of 800oP and whose three ends are blocked with trimethylsiloxy groups, and one molecule chain of methylhydrodiene with both ends blocked with trimethylsiloxy groups. Methylhydrodiene polysiloxane containing 95 moles of siloxy groups3.
0 parts (=81H/=SiVi =1.2 (mo, ratio))
and 1.0 part of a complex of chloroplatinic acid and vinyl siloxane (0.003 part of platinum equivalent) were added and mixed uniformly to prepare a silicone treatment bath, which was then treated in the same manner as in Example 3 to form a substrate. A silicone film was formed on top and the physical properties were compared, and the film formation time was 7 seconds.

The results showed a peeling force of 40 g and 15 m and a residual liquid ratio of 99 yen.

-27~

Claims (1)

[Claims] 1. a) At the molecular chain terminal or RR8iO-a Hydrocarbon group, a is 2
Or blocked with an organosiloxy group shown in 3). Organopolysiloxane represented by the general formula Rb5in4-b (R is the same or different unsubstituted or substituted monovalent hydrocarbon group, b is a positive number of ≦3) General formula RH810 to\od 4-c- d R is the same as above, O-d is a positive number, and organohydrodiene polysiloxane represented by o + d≦3) c) A silicone composition for mold release characterized by comprising platinum or a platinum-based compound catalyst. thing.