JPS6354412A - Photocurable resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which can give a cured film excellent in mechanical properties such as elongation and surface lubricity, by mixing a urethane (meth)acrylate oligomer with a reactive diluent, a photopolymerization initiator and a specified dialkylpolysiloxane. CONSTITUTION:The title composition of a viscosity (at 25 deg.C) of 10-10,000cP is obtained by mixing 100pts.wt. mixture of 90-99.9wt% mixture of 30-70wt% urethane (meth)acrylate oligomer (A) of a number-average MW of 500-10,000, having a urethane bond in the molecular skeleton and 2-6 (meth)acryloyl groups in the molecule with a reactive diluent (B) which is a compound having at least one, preferably, 1-6 polymerizable C-C double bonds in the molecule, an MW of 90-200, a viscosity (at 25 deg.C) of 2-2,000cP and being a lowly viscous liquid at room temperature with 10-0.1wt% dialkylpolysiloxane (C) of a number-average MW of 500-5,000, having a molecular skeleton comprising a 4C or lower alkyl group-containing dialkylpolysiloxane and having (meth) acryloyl groups on both ends with 0.1-10pts.wt. photopolymerization initiator (D).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photocurable resin composition useful as coating materials for fluxipul printed circuit boards, electronic parts, and the like.

(Conventional technology) Photocurable resin compositions save resources and energy.

In recent years, it has attracted particular attention as a curable material that can replace conventional thermosetting materials that use organic solvents from the viewpoint of being non-polluting.

Various types of photocurable resin compositions are known that use epoxy (meth)acrylate oligomers, polyester (meth)acrylate oligomers, urethane (meth)acrylate oligomers, etc. as main components. In particular, products using urethane (meth)acrylate oligomers provide cured coatings with high elongation and excellent mechanical strength, so they are expected to be applied to various applications such as flexible printed circuit boards and coating materials for electronic components. ing.

[Problem that the invention seeks to solve]

However, although the conventionally known photocurable resin compositions using the above-mentioned urethane (meth)acrylate oligomer as a main component have the characteristic of providing a cured coating film with high elongation, the coating film after curing is There is an inconvenience that a sticky feeling remains on the surface and the coating films adhere to each other, which makes it unavoidable to avoid disadvantages in use.

Therefore, the present invention solves the above-mentioned conventional problems and can be used as a coating material for flexible printed circuit boards and electronic components, which can form a cured coating film with high elongation and good slipperiness without surface tackiness. The purpose is to provide a particularly useful photocurable resin composition.

[Means for solving problems]

As a result of intensive studies to achieve the above object, the inventors discovered that in conventionally known photocurable resin compositions using urethane (meth)acrylate oligomers as a main component, a specific compound was further added as a curable component. It was discovered that when used in combination, a cured coating film with high elongation, excellent mechanical strength, and good slipperiness with no surface tackiness could be formed, leading to the completion of this invention.

That is, the present invention provides a urethane (meth)acrylate oligomer, b) a urethane (meth)acrylate oligomer, b) containing at least one polymerizable carbon-carbon double bond in one molecule that at least functions as a reactive diluent for component a. In a photocurable resin composition containing a compound that is liquid with low viscosity at room temperature and C) a photopolymerization initiator, the above a and b.

The present invention relates to a photocurable resin composition characterized in that, in addition to component C, d) sialgyl polysiloxane having (meth)acryloyl groups at both ends of the molecule is included.

In addition, in this specification, the (meth)acryloyl group refers to an acryloyl group and/or a methacryloyl group,
(Meth)acrylate means acrylate and/or methacrylate, and (meth)acrylic acid means acrylic acid and/or methacrylic acid, respectively.

In addition, the number average molecular weight (hereinafter referred to as MW) described in this specification refers to a value measured by gel permeation chromatography (GPC) using polystyrene as a standard, and viscosity refers to a value measured using a Brookfield viscometer. shall mean the values measured by, respectively.

(Structure and operation of the invention) The urethane (meth)acrylate oligomer as component a used in this invention has a urethane bond in its molecular skeleton, and has two or more (meth)acryloyl bonds in the molecule, usually up to six. generally has a MW of 500 to 10
,000, which broadly includes conventionally known urethane (meth)acrylate oligomers.

Examples include urethane (meth)acrylate oligomers such as polyether, polyester, polycaprolactone, and polycarbonate.

These urethane (meth)acrylate oligomers are
Compared to other (meth)acrylate oligomers used in UV-curable materials, it has the advantage of providing a cured coating film with greater elongation and good mechanical strength. However, the combination of this and a reactive diluent as component b causes a problem in terms of the slipperiness of the cured coating film. Therefore,
In this invention, the above-mentioned characteristics are improved by using a specific curable component as the d component, which will be described later.

The above urethane (meth)acrylate oligomer can be produced by using, for example, a polyether polyol, polyester polyol, polycaprolactone polyol, polycarbonate polyol, etc. as a polyol component, and reacting these polyols with a diisocyanate compound and further with a hydroxyalkyl (meth)acrylate. can be obtained by

Examples of the above diisocyanate compounds include tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, isophorone diisocyanate, bis(isocyanate methyl)cyclohexane, dicyclohexylmethane diisocyanate, and 1,6-hexane diisocyanate, each having a molecular weight of 150 to 1.00.
Various compounds of about 0 are used. Moreover, as the above-mentioned hydroxyalkyl (meth)acrylate, those having a hydroxyalkyl group having about 2 to 5 carbon atoms, such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate, are used.

Since the urethane (meth)acrylate oligomer as the above-mentioned component a is usually solid or has a high viscosity at room temperature, the component b used in this invention is a compound that is liquid with low viscosity at room temperature. It is used to improve workability, but it also acts as an effective component to adjust the flexibility and hardness of the cured coating film.

As the b component, a compound having one or more polymerizable carbon-carbon double bonds, preferably 1 to 6 polymerizable carbon-carbon double bonds in the molecule and which is a low viscosity liquid at room temperature is used. is 2 to 2,000 centivoices (cps)/2
This refers to temperatures within a range of approximately 5℃. These compounds are not limited to one type, and two or more types can be used in combination, but when used in combination, the properties of the mixture should be as described above. Therefore, one of them may be solid or have high viscosity at room temperature. The molecular weight of this b acid component is usually 90 to 2.
．． It is about 000.

Specific examples of the above-mentioned components include those having a (meth)acryloyl group as a polymerizable carbon-carbon double bond, such as 2
- Ethylhexyl (meth)acrylate, tetrahydrofurfuryl alcohol caprolactone adduct (meth)
Acrylate, (meth)acrylate of nonylphenol ethylene oxide adduct, polyethylene glycol di(meth)acrylate, polybrobylene glycol di(meth)acrylate, bisphenol diethylene glycol di(meth)acrylate, hydrogenated bisphenol triethylene glycol di(meth)acrylate , alicyclic di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri
(meth)acrylate, mono- to poly(meth)acrylate such as epoxy (meth)acrylate synthesized from bisphenol diglycidyl ether, and the like.

In addition, the above-mentioned components include allyl esters such as diallyl adipate, diallyl phthalate, triallyl trimellitate, and triallyl isocyanurate, styrene, vinyl acetate, N-vinylpyrrolidone, N-N-dimethylacrylamide, N・N-dimethyl Vinyl compounds such as aminopropylacrylamide and N-N-dimethylaminoethyl acrylate can also be used.

The d component used in this invention has a molecular skeleton of dialkylpolysiloxane in which the alkyl group usually has up to 4 carbon atoms, with dimethylpolysiloxane being a typical example, and (meth)acryloyl groups are introduced at both ends of the molecule. Naru MW
is usually about 500 to 5,000. By using such component d in combination with components a and b, the slipperiness of the coating film surface can be greatly improved without impairing physical properties such as elongation of the cured coating film.

In this invention, the above-mentioned components a, b, and d are used together as curable components, and the ratio of each component is 190 to 99.9% by weight, preferably 95 to 99.9% by weight of the total of components a and b. d component is 10 to 99.7% by weight
The amount of the d component should be 0.1% by weight, preferably 5 to 0.3% by weight. If the amount of the d component is too low, the above-mentioned effect cannot be expected, and if it is too high, the cured coating film will become opaque. There is a risk that the phase may become uneven. Note that the mutual ratio of components a and b can be appropriately set depending on the type of each component from the viewpoint of physical properties and coating workability of the cured coating film.

Generally, the a component is 30 to 70 of the total amount of a and b components.
It is preferable to set the ratio to be % by weight.

As the photopolymerization initiator used as component C in this invention, various kinds of initiators generally used as initiators and sensitizers for ultraviolet curable coatings can be used. For example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, 2-methylbenzoin, benzophenone, Michler's ketone, benzyl, benzyl dimethyl ketal, benzyl diethyl ketal, anthraquinone, methylanthraquinone, 2,2-jethoxyacetophenone, 2-methylthioxanthone, 2-isopropylthioxanthone, 2-lyrorothioxanthone, anthracene, 1,1-dichloroacetophenone, methylorthobenzoylbenzoate, etc., and those used in combination with small amounts of sensitizing aids such as amines, etc. can be mentioned.

The amounts of these photopolymerization initiators used include a, b,
Usually 0.1 to 10 parts by weight per 100 parts by weight of the total amount of component d.
The amount is about 1 to 5 parts by weight, preferably 1 to 5 parts by weight. If this amount is too small, the curability cannot be satisfied, and even if it is used in excess of a predetermined amount, no further improvement in the curing rate can be expected.

The photocurable resin composition of this invention has the above a.

It is made by uniformly mixing and dissolving components b, c, and d, but this composition may contain, if necessary, known (meth)acrylate oligomers other than component a, as well as various modifying resins, Various additives such as surfactants can be added.

The photocurable resin composition of the present invention constructed as described above usually has an overall viscosity of 10 to 10.00 Ocps (25
It is desirable that the temperature be adjusted to within a range of about 30°F (℃). After this composition is applied to the object, it can be cured by simply irradiating it with light such as ultraviolet rays according to a known method, resulting in good surface slipperiness and excellent mechanical properties such as elongation. A cured coating is formed.

[Effect of the invention] As described above, in this invention, urethane (meth)
By incorporating a dialkyl polysiloxane having (meth)acryloyl groups at both molecular ends as the d component into a photocurable resin composition that uses an acrylate oligomer as a main component, surface slip properties are good. ,
Moreover, since it is possible to form a cured coating film with excellent mechanical properties such as elongation, the photocurable resin composition can be advantageously applied to various applications such as flexible printed circuit boards and coating materials for electronic components. can be provided.

〔Example〕

EXAMPLES Below, examples of the present invention will be described in more detail. In addition, in the following, parts shall mean parts by weight.

Example 1 50 parts of urethane acrylate oligomer synthesized from polytetramethylene glycol (MWI, 000), tolylene diisocyanate and 2-hydroxyethyl acrylate, 50 parts of bisphenol diethylene glycol diacrylate, MWI.

000 dimethylpolysiloxane diacrylate 2 parts,
3 parts benzophenone and 1 part diethylaminoethanol
A photocurable resin composition having a viscosity of 6,400 cps (25° C.) was obtained by dissolving and mixing the following parts.

Comparative Example 1 The viscosity was 6.500 cp in the same manner as in Example 1 except that dimethylpolysiloxane diacrylate was not used.
! A photocurable resin composition of No. 1 (25° C.) was obtained.

Example 2 Urethane acrylate oligomer 5 synthesized from polycaprolactone diol (MW 2,000), tolylene diisocyanate, and 2-hydroxyethyl acrylate
0 parts of bisphenol diethylene glycol diacrylate, 1 part of dimethylpolysiloxane diacrylate with MWI of 000, 3 parts of benzophenone, and 1 part of diethylaminoethanol were dissolved and mixed to obtain a viscosity of 7.0O.
A photocurable resin composition of Ocps (25°C) was obtained.

Comparative Example 2 The viscosity was 7.050 cp in the same manner as in Example 2 except that dimethylpolysiloxane diacrylate was not used.
A photocurable resin composition of 25° C. was obtained.

Example 3 Polyester polyol (MWI, 000) made from ethylene glycol and adipic acid, 50 parts of urethane acrylate oligomer synthesized from tolylene diisocyanate and 2-hydroxyethyl acrylate, 50 parts of bisphenol diethylene glycol diacrylate, MWI, 000 0.5 parts of dimethylpolysiloxane diacrylate, 3 parts of benzophenone and 1 part of diethylaminoethanol were dissolved and mixed to give a viscosity of 4.000 cp.
A photocurable composition of 25° C. was obtained.

Comparative Example 3 The viscosity was 4.000 cp in the same manner as in Example 3 except that dimethylpolysiloxane diacrylate was not used.
A photocurable resin composition of 25° C. was obtained.

Each of the photocurable resin compositions of Examples 1 to 3 and Comparative Examples 1 to 3 above was placed on a glass plate. Apply to a thickness of I m, and use a high-pressure mercury lamp (80w/am) to apply an irradiation dose of 500mJ.
/cd, and the elongation of each cured coating film and the slipperiness of the coating film surface were examined. In addition, the measurement of elongation is based on JIS K7.
113.

In addition, the slipperiness of the paint film surface is evaluated as ○ if the paint films do not stick to each other at all when the paint films are stacked together at 25℃ for 1 hour, and the paint films do not stick to each other. Cases where the paint film remained sticky and the paint films adhered to each other were evaluated as x.

As is clear from the above test results, the photocurable resin composition according to the present invention can form a cured coating film that has high elongation and excellent slipperiness on the coating surface. I understand.

Claims (1)

[Claims] (1) a) Urethane (meth)acrylate oligomer,
b) A compound that is liquid at room temperature and has a low viscosity and contains one or more polymerizable carbon-carbon double bonds in one molecule, which has at least the effect of acting as a reactive diluent for component a, and c) a photopolymerization initiator. In the photocurable resin composition containing the above a, b, c
A photocurable resin composition characterized in that, in addition to the components, d) a dialkylpolysiloxane having (meth)acryloyl groups at both ends of the molecule.