JPH03181509A - Photo-setting type organopolysiloxane composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition, composed of a specific organopolysiloxane and polymerization catalyst in a specified proportion, curable at low temperatures, excellent in solvent, water and heat resistance and useful as films, coatings, tacky agents, etc., in electrical, electronic and chemical industries. CONSTITUTION:The objective composition containing (A) 100 pts.wt. organopolysiloxane expressed by the formula [R1 is H or methyl; R2 and R3 are (substituted) monofunctional hydrocarbon; a, b and c are 1-6; d is 1-200; n is 1-4] and (B) 0.01-10 pts.wt. polymerization catalyst (e.g. azobisisobutyronitrile). Furthermore, the component (B) is preferably composed of 0.01-10 pts.wt. photochemical reaction initiator and 0.01-10 pts.wt. sensitizer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photocurable organopolysiloxane composition used as a film, paint, adhesive, etc. in industrial fields such as the electrical/electronic industry and the chemical industry.

[Conventional technology]

Generally, solvent-soluble organopolysiloxane compositions are known as paints exhibiting excellent weather resistance, or as punching materials and adhesives in the electrical and electronic industries. Most of these organopolysiloxane compositions are thermosetting, and silicone gel is heated to 80 to 150°C in the presence of a platinum catalyst to add hydrogen to unsaturated groups bonded to silicon atoms. Atom is added and mold hardening is performed.

For this reason, there is a drawback that the curing temperature is too high to be used in electronic parts with poor heat resistance.In addition, the silicone gel does not react with sulfur, tin, antimony, mercury, bismuth, or solder flux when heated. Since the reaction inhibits the curing, manufacturing control is complicated. Furthermore, when the organopolysiloxane composition is thermally cured, volumetric shrinkage occurs, causing problems such as cranking or destruction of the base material and electronic components.

On the other hand, silicone used as a paint is a low-molecular organopolysiloxane composition made solvent-soluble and heated in the presence of a platinum catalyst or the like to undergo a polymerization reaction. However, there is a problem in terms of environmental hygiene in that harmful solvents are vaporized by the heating associated with this polymerization reaction.

Problems to be developed by Invention C] This invention can be used for electronic parts with poor heat resistance, and can also be developed by methods other than heating to prevent them from reacting with other substances or causing cracks due to heating. The object of the present invention is to obtain a photocurable organopolysiloxane composition that is cured by promoting a polymerization reaction.

Means for Solving Problem C] In order to solve the above problem, in this invention, (wherein R1 is a hydrogen atom or a methyl group, Rz and Rj are the same or different unsubstituted or substituted monovalent carbon hydrogen group,
a, b, and c are positive integers of 1 to 6, d is a positive integer of 1 to 200, and n is a positive integer of 1 to 4), 100 parts by weight of an organopolysiloxane, and 0.0 parts by weight of a polymerization catalyst. 01-10
Parts by weight of the photocurable organopolysiloxane composition are prepared.

In addition, the photocurable organopolysiloxane composition has the formula (n) RR+ (wherein, R is a methyl group or a hydrogen atom, R,, R8 are the same or different unsubstituted or substituted monovalent hydrocarbon groups, or phenyl group, a and b are positive integers of 1 to 4, n is 1 to 4;
A method containing 100 parts by weight of an organopolysiloxane (a positive integer of 200) and 0.01 to 10 parts by weight of a polymerization catalyst may be adopted, and a mixture containing 100 parts by weight of the above two types of organopolysiloxanes may be adopted. The polymerization catalyst may be a photocurable organopolysiloxane composition containing 0.01 to 10 parts by weight of a photoinitiator and 0.01 to 10 parts by weight of a polymerization catalyst. 0.01~10
It may also be composed of parts by weight. The details will be described below.

First, as an example of synthesis of the organopolysiloxane used in this invention, reaction with Ani diisocyanates 1 mole of polydimethylsiloxanes containing hydroxyl groups and 2 moles of diisocyanates are reacted, and further hydroxyl groups are added at one end. B: Reaction with an acrylic monomer containing isocyanate groups.C: Reaction with 2 moles of an acrylic monomer containing isocyanate groups. : Reaction with an acrylic monomer containing a carboxyl group An example is a reaction between 1 mole of polydimethylsiloxane containing a hydroxyl group and 2 moles of an acrylic monomer containing a carboxyl group.

Here, the structural unit of polydimethylsiloxane containing a hydroxyl group consists of a combination of p + Ro (Ro is hydrogen or the same or different organic group), and its form may be silicone oil, silicone rubber, or silicone resin. and,
The above silicone oil has D units as the main chain and M units as the ends, and silicone rubber is a long-chain polymer consisting only of D units, and a phenyl group is introduced into Ro, resulting in heat resistance and cold resistance. In addition, the silicone resin exhibits a three-dimensional linear structure containing a large amount of T units, and in order to improve cold resistance and heat resistance, Ro has a methyl group,
Phenyl groups and mixtures of both, such as phenylmethyl silicone resins, are suitable.

Further, as the diisocyanates, trirediisocyanate (↑DI), 4. 4'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), metaxylylene diisocyanate (MXDI), hexamethylene diisocyanate)
()101), 2. 6-dicyanatomethylcabronate (LDI), 4. 4'-methylenebis(cyclohexyl)isocyanate (II+zM■
), hydrogenated methylcyclohexane, isophorone diisocyanate (IPDI), I-lymethylhexamethylene diisocyanate (IMDI), dimer acid diisocyanate (DDr), and the like.

In addition, as an acrylic monomer containing a hydroxyl group, 2
-hydroxyethyl acrylate) (211EA), 2
-Hydroxyethyl methacrylate (211HMA),
2-hydroxypropyl acrylate (21 (PA) or 2-hydroxypropyl methacrylate (28PM)
A) etc.

As the isocyanate group-containing acrylic monomer, 2-
Examples include ethyl isocyanate methacrylate, 2-ethyl isocyanate acrylate, isocyanate acrylate, and isocyanate methacrylate.

Furthermore, the organopolysiloxane synthesis examples A-C mentioned above
Table 1 shows the reaction catalyst, polymerization inhibitor, and solvent added therein.

Examples of the polymerization catalyst include a photoreaction initiator for ultraviolet irradiation, a sensitizer, azobisisobutyronitrile (AIBN) as a polymerization initiator, and a reaction initiator for electron beam irradiation. These polymerization catalysts are added in an amount of 0.01 to 10 parts by weight per 100 parts by weight of the organopolysiloxane. This is because if it is less than 0.01 part by weight, the reaction is slow;
This is because if it is 10 parts by weight or more, the decomposition of the light anti-oxidant initiator will be rapid, resulting in increased odor, residual fragrance, etc.

[Effect]

The photocurable organopolysiloxane composition according to the present invention configured as described above contains a polymerization catalyst, and can be heated by methods such as ultraviolet irradiation, electron beam irradiation, suspension polymerization, and solution polymerization. It hardens without any problem.

〔Example〕

Examples and comparative examples of the present invention will be shown below, and the parts in the formulations mean important parts unless otherwise specified.

Example 1: As the organopolysiloxane, the above synthesis examples consisting of the following (1) to (2) were used.

■Polydimethylsiloxane (manufactured by Shin-Etsu Chemical: X-22
160AS) 831 copies ■RD+ 336
Part ■2-HEA 23
2 parts ■ Dibutyltin dilaurate 0.1
Part ■ Hydroquinone 0.1 part ■ Photoreaction initiator (Coilgacure 65 manufactured by Chiha Geigy)
1) 70 copies above■
, ■ and ■ were reacted at 60°C for 2 hours, and then 8
React at 0℃ for 2 hours, then add ■ and ■ and heat at 80℃.
While reacting with C, the progress of the reaction was observed using an infrared absorption spectrum, and the completion of the reaction was confirmed by the disappearance of the absorption peak of the isocyanate group. Next, 70 parts of ■ were added to the reaction product, and this was applied to a PUT film with a thickness of 50 μm to give a thickness of 1 to 5−, and then heated using a high-pressure mercury lamp (
The curing reaction was completed by irradiating at 80 W/cm for 0 seconds from a height of 1, Q cm.

Example 2: As the organopolysiloxane, the above-mentioned Synthesis Example B consisting of the following (1) to (2) is used.

■Polydimethylsiloxane (manufactured by Shin-Etsu Chemical: X-22
-160AS) 83
1 part ■ 2-ethyl isocyanate methacrylate 310
Part ■Diptyltin dilaure) 0.1 part■
Hydroquinone 0.1 part ■Photoreaction initiator (Nilgacure manufactured by Ciba Geigy)
651)
55 parts The above ① to ③ were reacted at 60°C for 2 hours, and then further reacted at 80°C for 4 hours, then ① was added, and while the reaction was carried out at 80°C, the progress of the reaction was observed using an infrared absorption spectrum. Thereafter, the same operations as in Example 1 were performed.

Example 3: As the organopolysiloxane, the above-mentioned Synthesis Example C consisting of the following (1) to (2) is used.

■Vol/dimethylsiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.: X-2
2160AS) 831
Parts ■ Acrylic acid 144 parts ■ Baratorue〉' Sulfonomitsu 20
Part ■Hydroquinone Part 2■
1,500 parts of luene ■ 70 parts of Niirgacure 651 (manufactured by Ciba Geigy) were reacted at 110° C. while cooling under reflux for 10 hours, and 36 parts were dehydrated to terminate the reaction. 70 parts of (1) was added to the reaction product, which was applied to a PUT film, and the same operations as in Example 1 were carried out.

Example 4: A case where organopolysiloxane synthesis example A of Example 1 is subjected to polymerization will be described.

■ Organopolysiloxaf Synthesis Example A (used in Example 1) 10 parts ■ 2-ethylhexol acrylate 20 parts ■ Butyl methacrylate 60 parts ■ Styrene 10 parts ■ Polymerization initiator (AIBll) 2 parts ■
Dispersant (gelatin) 1 part Dispersant (dibasic sodium phosphate) 0.1 part Water
500 parts of the above (1) to (2) were placed in a suitable container, the temperature inside the container was set at 75-80°C, and the above (1) to (3) were added dropwise using a dropping funnel, and the mixture was further reacted at the same temperature for 8 hours. The produced polymer was taken out and dried under reduced pressure at 50°C in the form of a film.

Example 5 and Example 6: In Examples 5 and 6, 10 parts of organopolysiloxane synthesis example B of Example 2 or organopolysiloxane C of Example 3 was used in place of sample ■ of Example 4. Film-like polymers were obtained in the same manner as in Example 4, except for the following.

Comparative Example 1: ■ 10 parts of trimethylolpropane triacrylate ■ 20 parts of 2-ethylhexyl acrylate ■ 60 parts of butyl methacrylate ■ 10 parts of 2-hydroxomethacrylate ■ Photoreaction initiator (Nilgacure manufactured by Ciba Geigy)
651)
A polymer film was formed on a PET film in the same manner as in Examples 1 to 3 using 5 parts of the liquid mixtures (1) to (2) above.

Comparative Example 2: Organopolysiloxane (Synthesis Example A) 10 of Example 4
Trimethylolpropane triacrylate-N instead of
A film-like polymer was prepared in exactly the same manner as in Example 4 except that 0 part was used.

The physical properties of the films obtained in Examples 1 to 6 and Comparative Examples 1 and 2 are summarized in Table 2. The evaluation method for each physical property is as follows.

Solvent resistance: 1 g of film in 100 g of ethylene acetate at room temperature
The samples were allowed to stand for a period of time and their solubility was compared.

○ Insoluble Δ -- Dissolution or swelling × Complete dissolution Water resistance; 1 g of film was immersed in tap water at room temperature for 24 hours, and the whitening properties were compared.

○ No whitening △ Partial whitening Complete whitening Heat resistance: It was left to dry at 150° C. for 1 hour, and a yellowing test was conducted.

○ No yellowing △ - Yellowing × Complete yellowing As is clear from Table 2, the photocurable organopolysiloxane compositions of Examples 1 to 6 were obtained without heat curing. The film had excellent solvent resistance, water resistance, heat resistance, and elastic properties, making it highly versatile.

Table 1 [Effects] The photocurable organopolysiloxane composition of the present invention is as follows:
As explained above, the polymerization reaction is accelerated and cured by operation at relatively low temperatures or non-heating operations such as ultraviolet irradiation, resulting in a product with excellent solvent resistance, water resistance, and heat resistance. It has high industrial value and can be applied to a wide range of fields such as the electrical/electronic industry and the chemical industry.

Claims (4)

[Claims] (1) Formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ …(I) (In the formula, R_1 is a hydrogen atom or a methyl group, R_2, R
_3 is the same or different unsubstituted or substituted monovalent hydrocarbon group, a, b, c are positive integers of 1 to 6, d is 1 to 200
100 parts by weight of an organopolysiloxane (n is a positive integer of 1 to 4) and 0.01 parts by weight of a polymerization catalyst.
10 parts by weight of a photocurable organopolysiloxane composition. (2) Formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) (In the formula, R is a methyl group or a hydrogen atom, R_1, R_2
is the same or different unsubstituted or substituted monovalent hydrocarbon group or phenyl group, a and b are positive integers of 1 to 4, and n is a positive integer of 1 to 200) Organopolysiloxane 100 weight 1 part by weight of a polymerization catalyst and 0.01 to 10 parts by weight of a polymerization catalyst. (3) A photocurable organoorganic product comprising 100 parts by weight of a mixture containing organopolysiloxanes represented by formulas (I) and (II) above, and 0.01 to 10 parts by weight of a polymerization catalyst. Polysiloxane composition. (4) Claim 1 in which the polymerization catalyst comprises 0.01 to 10 parts by weight of a photoreaction initiator and 0.01 to 10 parts by weight of a sensitizer.
, 2 or 3, the photocurable organopolysiloxane composition.