JPS5823812A - Ultraviolet-curing resin composition - Google Patents

Abstract

PURPOSE:To prepare the titled composition having excellent adhesivity, by compounding a compound containing ethylenic unsaturated group with a copolymer composed of a specific monofunctional acrylic monomer and an ethylenic unsaturated monomer, at a specific ratio, and adding a photo-sensitizer to the composition. CONSTITUTION:The objective composition is prepared by compounding (A) a compound containing ethylenic unsaturated group (e.g. ester of a polyhydric alcohol and a polybasic acid, etc.) with (B) a copolymer having an average molecular weight of 1,000-10,000 and derived from (i) 0.5-10wt% acrylic monomer of formula(R1 is H or CH3; R2 and R3 are H or alkyl; n is 1-3)[e.g. dimethylaminoethyl (meth)acrylate]and (ii) 99.5-90% ethylenic unsaturated monomer[e.g. acyclic alkyl eater of (meth)acrylic acid], at a weight ratio (A)/(B) of 95:5-60:40, and adding a photo-sensitizer (e.g. benzophenone) to the above mixture. EFFECT:It has excellent adhesivity especially to a molded article of a PET resin based on terephthalic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin composition that is cured by ultraviolet light. More specifically, the present invention provides a resin composition that cures with ultraviolet rays and has excellent adhesion to various substrates, especially substrates such as films and molded products made of polyethylene terephthalate (hereinafter abbreviated as PET) resin. be. Conventional plastic films, plastic moldings, etc. differ in chemical structure, molecular weight, molecular weight distribution, shape of the main chain of the molecular structure, presence or absence of polarity, stereoregularity, etc. depending on the materials used, but the surface of these base materials For example, surface treatment with solvents, coupling agents, surfactants, etc., chromic acid mixture treatment, phosphoric acid solution treatment, satinizing method, etc. are used to improve adhesion to the substrate when coating. Wet processing method or
Dry treatments such as corona discharge treatment, ultraviolet irradiation treatment, gas flame treatment, and plasma treatment have been used, and the same applies to films and molded products made of PET resin. However, when using the above-mentioned wet processing method, there is a problem in terms of pollution caused by the discharge of the processing liquid, and dry processing requires physical means to partially change the polarity, shape, etc. of the surface of the shiburastic. In addition, there is a strong desire to shorten the process from the standpoint of energy and resource conservation, as well as the difficulty of sufficiently processing highly processed molded products such as those with complex shapes. A better composition was desired.

In order to solve these problems, i.e., to improve the adhesion with plastic films or molded objects without physical or chemical treatment, a composition that can be cured by ultraviolet rays is applied, and a film is formed by irradiating the composition with ultraviolet rays. It has been proposed (Japanese Unexamined Patent Publication No. 49-128067). However, although this method is effective to some extent for polyolefin resin, it is not effective for films like untreated PET resin.
No effect of improving adhesion was observed in the molded product.

As a result of extensive research into methods for improving the adhesion to untreated PET resins, the inventors completed the ultraviolet curable resin composition of the present invention.

As a resin composition that satisfies the above object, an ultraviolet curable resin composition comprising a compound (A) having at least one ethylenically unsaturated group in the molecule and a photopolymerizable sensitizer is used.
B) s (In the formula, R1 is a hydrogen atom or a methyl group, Rt and Rx are the same or different from each other, and each is a hydrogen atom or an alkyl group, and n is 1 to
0.5 of the acrylic monomer (B) represented by
Weight 2 or more, 10% by weight or less 1 and ethylenically unsaturated monomer copolymerizable with (B) 90% by weight or more 99.5
The number average molecular weight obtained by copolymerization is 1000% by weight or less.
An ultraviolet curable resin composition with improved adhesion, characterized by mixing copolymer (C) of ~10,000 so that (A): (C) = 95:5 ~ 60:40 (weight ratio) It provides:

In the present invention, a polyester resin obtained by polycondensation of PET resin, which is a typical base material, and terentalic acid or terephthalic acid lower alkyl ester and ethylene glycol, and has an intrinsic viscosity of 0.3 to 0.・
Resins within the range of No. 9 are typical, but resins in which other components such as isophthalic acid are copolymerized as raw materials in addition to the above-mentioned main raw materials are also included.

In the present invention, the compound (A) having at least one ethylenically unsaturated group in the molecule only needs to have a polymerizable ethylenically unsaturated group, but for example, (a) polyhydric alcohol and (b) polyesters which are esters of hydroxyl-terminated carboxylic acid and ethylenically unsaturated carboxylic acid with various degrees of polymerization obtained by condensing polyhydric alcohol and polybasic acid. (C) polyurethane polyvinyl compound obtained by addition reaction of polyvalent incyanate and hydroxyl group-containing ethylenically unsaturated monomer, (d) polyhydric alcohol and polybasic acid with various degrees of polymerization. A polyurethane-based polyvinyl compound obtained by addition reaction of a hydroxyl group-containing ethylenically unsaturated monomer to an adduct of either a hydroxyl group-terminated ester or a polyhydric alcohol and an excess equivalent of a polyhydric incyanate, (e) Examples include epoxy-based polyvalent vinyl compounds obtained by addition-reacting ethylenically unsaturated carboxylic acids to polyvalent epoxy resins. In the present invention, these compounds can of course be used alone, but also
A mixture of two or more types can also be used.

The photopolymerization sensitizer used in the present invention may be any substance that generates photoresist radicals, but typical examples include benzoin-based sensitizers such as benzoin methyl ether and benzoin butyl ether; Ketone sensitizers such as toxyacetophenone, p-chlorobenzophenone, benzophenone, azobisin butyronitrile,
2. Photopolymerization sensitizers such as azo compound sensitizers such as 2'-azobis-(,2,4-dimethylvaleronitrile)azobenzene and quinone sensitizers such as anthraquinone and phenanthraquinone are Among these, benzophenone photopolymerizable sensitizers are preferred in the present invention from the viewpoint of adhesion to the substrate.

In the present invention, the monofunctional acrylic monomer represented by the general formula (B) includes, for example, diethylamine ethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, dibutylaminoethyl (meth)acrylate,
Tertiary nitrogen atom-containing (meth)acrylic acid esters such as dibutylaminoprobyl (meth)acrylate, dicyclohexylaminoethyl (meth)acrylate, tertiary-butylaminoethyl (meth)acrylate,
Examples include secondary nitrogen atom-containing (meth)acrylic acid esters such as ethylaminoethyl (meth)acrylate,
Among these, tertiary nitrogen atom-containing (meth)acrylic acid esters are preferred from the viewpoint of adhesion to the cutting base material, and dimethylamine ethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, etc. are particularly preferred.

Typical ethylenically unsaturated monomers copolymerizable with (B) in the present invention include, for example, aliphatic or aliphatic Ili group alkyl esters of acrylic acid or methacrylic acid, where the alkyl group is, for example, a methyl group or an ethyl group. ,n
-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, 2-ethylhexyl group,
Examples include lauryl group and cyclohexyl group.

Also mentioned are dialkyl esters of fumar having 1 to 4 carbon atoms. Typical examples of other copolymerizable ethylenically unsaturated monomers include aromatic vinyl compounds such as styrene and α-methylstyrene, (meth)acrylamide and (meth)acrylonitrile. Among these vinyl compounds, particularly in the present invention, alkyl esters of acrylic acid or methacrylic acid, particularly acyclic alkyl esters, are highly copolymerizable with the monomer (B) and copolymerizable with the compound (A) in the present invention. Preferred from the viewpoint of compatibility with (C).

In the present invention, the copolymerization ratio of the monofunctional acrylic monomer (B) in the copolymer (C) obtained by copolymerizing the monomers represented by the general formula (B) is 0.5% by weight or more and 10% by weight or more. % by weight or less, preferably 2% by weight or more and 8% by weight or less. When the amount of the acrylic monomer represented by formula (B) in the copolymer (Q) is less than 0.5% by weight, it is resistant to ultraviolet rays. A well-cured coating film has insufficient adhesion to the substrate and cannot be used as the ultraviolet curable resin composition of the present invention.Also, when the amount is more than 10% by weight, the adhesion of the ultraviolet-cured coating film to the substrate is insufficient. Although the adhesion is good, it cannot be used as the ultraviolet curable resin composition of the present invention because it causes problems such as whitening of the cured coating under high humidity.

(value in terms of listyrene) is 1,000 or more and 10,000 or less. In particular, from the point of view of adhesion to the base material, 2000 or more 60
A value in the range of 00 or less is preferable.

When the number average molecular weight is less than 1000, the adhesion to the substrate is poor. Also, when the number average molecular weight is greater than 10,000,
Not only does the compatibility with the compound (A) deteriorate, but also the adhesion to the base material deteriorates.

In the present invention, the mixing ratio of compound (A) and copolymer (C) is (A):(C) in a weight ratio of 95:5 to 60:40, preferably 85:15 to 65:35. Copolymer (C) is 5
When the amount is less than % by weight, the adhesion to the base material is poor.

In addition, when the copolymer (C) is more than 40% by weight, the adhesion is good, but the cured coating film is not sufficiently cross-linked, and the chemical resistance and
Since the solvent resistance is poor, it cannot be used as the ultraviolet curable resin composition of the present invention.

In the present invention, the copolymer (Q) can be polymerized by various means and methods such as radical polymerization, ionic polymerization, solution polymerization, bulk polymerization, batch polymerization, continuous polymerization, etc. Methods include - speaking;
The division method, the continuous method, and the polymerization of any one or two of the monofunctional unsaturated monomers represented by the general formula (B) and the ethylenically unsaturated monomers copolymerizable therewith are carried out, and the remaining Various methods and combinations of these various means and methods can be arbitrarily adopted as desired, but in general, azo-based initiators, peroxide-based initiators, etc. Solution polymerization by radical polymerization using an agent or the like is preferable in terms of reaction control and versatility. The polymerization temperature at this time is usually preferably about 60°C to 150°C, and the polymerization may be carried out by selecting a temperature depending on the raw material monomers and other auxiliary raw materials. Typical radical polymerization initiators used to obtain the copolymer (C) of the present invention by radical polymerization include peroxides such as benzoyl peroxide and methyl ethyl ketone peroxide; Examples of typical chain transfer agents include mercaptans such as mercaptoethanol and l-dodecylmercaptan.

Typical polymerization solvents include aromatic solvents such as toluene and xylene, alcohol solvents such as inpropyl alcohol, ester solvents such as ethyl acetate and monobutyl acetate, and ketone solvents such as methyl ethyl ketone.

Next, various additives such as leveling agents, antifoaming agents, surfactants, various other auxiliary agents, organic solvents, etc. may be added to the ultraviolet curable resin composition of the present invention as necessary to improve workability. It can also be used as an additive for the purpose of adjusting the properties of the film, improving the properties of the film, etc., as long as it does not impede the effects of the present invention.

Next, any method can be used to form a film of the ultraviolet curable resin composition of the present invention on a substrate, such as coating by dipping the substrate, coating with a spray gun, roll coater, etc. Typical methods include methods using a flow coater, a clavia coater, and the like.

The ultraviolet rays necessary for curing the ultraviolet curable resin composition of the present invention are photochemically active electromagnetic waves with a wavelength of usually 200 nm.
~500 nm.

As the light source for this ultraviolet light, commonly used ones such as a carbon arc lamp, an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, an ultraviolet fluorescent lamp, a xenon lamp, etc. can be used. The time required for irradiation depends on the type and content of the photosensitizer used in the ultraviolet curable resin composition, the type and output of the light source used for irradiation, the distance from the light source to the object to be coated, and other conditions. Although it is different, it can be done in a few seconds by adjusting these conditions.

The ultraviolet curable resin composition of the present invention includes a PET resin base material,
For example, it can be used as a transparent protective coat for film moldings, a colored protective coat, and as an inder for printing inks.

Next, the present invention will be explained with reference to Examples and Comparative Examples, but the present invention is not limited to the Examples. In these, unless otherwise specified, parts or proportions are based on weight.

Example 1 Toluene 25 was placed in a flask equipped with a stirrer, a thermometer, a condenser, a dropping funnel, and a nitrogen gas blowing device on the top.
Add 0 parts and continue stirring and blowing nitrogen gas until 9.
Raise the temperature to 0°C. Next, while maintaining the temperature at 85°C to 90°C, 550 parts of methyl methacrylate, 400 parts of butyl acrylate, and 5 parts of diethylaminoethyl methacrylate were added.
A mixture of 0 parts of azobisisobutyronitrile and 40 parts of azobisisobutyronitrile was added dropwise from the dropping funnel for 3 hours, and the reaction was continued at the same temperature for 6 hours to obtain a number average molecular weight of 4.
000, acrylic copolymer (I) with a non-volatile content of 8.0%
I got it. Using this copolymer (1) as copolymer (C), an ultraviolet curable resin composition was produced with the following formulation. 31.3 parts of copolymer (I) as compound (A)
Composition (2) of the present invention was prepared by blending 50 parts of 7rA-1050 (product manufactured by Mitsui Toatsu Chemical (2), polyester oligomer), 25 parts of neopentyl glycol diacrylate, and 3 parts of benzophenone as a photopolymerization sensitizer. This combination (5
)=(The blending ratio of Q was 75:25.

Next, a transparent polyester film with a thickness of 25μ
The composition of the present invention (2) was coated on a commercially available product, Lumirror #25, in an amount to give a film thickness of 2,097 m'' with a coater, and was heated to a height of 12 cm using a commercially available high-pressure mercury lamp (80 W/em).
The film was cured by irradiating it with ultraviolet light for about 4 seconds.

The properties of this coating film are shown in Table 1.

Example 2 Similarly to Example 1, an ultraviolet curable resin composition ■ was prepared with the following formulation.
was manufactured.

Copolymer (1), 43.7
5 parts Orester RA-105050, 0 parts trimethylolpropane triacrylate) 1
The ratio in the 5.0 parts ratio was (C) = 65:35.

This composition (2) was cured by irradiation with ultraviolet rays in the same manner as in Example 1. The properties of this coating film are shown in Table 1.

Example 3 A mixture of 600 parts of methyl methacrylate and ethyl acrylate was used in place of the mixture in Example 1, except that the number average molecular weight was 5500s and the non-volatile content was 80.
% copolymer (It) was obtained.

Using this copolymer (II), composition ■
was manufactured.

Copolymer (II) 18, 75 parts Olestar RA-105050, 0 parts Neopentyl glycol diacrylate) 35.0
Part Benzophenone 3.0 Part 10
(A):(C)=85:15 in 6.75 parts.

This composition (1) was cured by irradiating it with ultraviolet rays in the same manner as in Example 1. The properties of this coating film are shown in Table 1.

Example 4 600 parts of methyl methacrylate, 380 parts of butyl acrylate, 20 parts of diethylaminoethyl methacrylate
A copolymer I having a number average molecular weight of 2300 and a non-volatile content of 80% was prepared in the same manner as in Example 1, except that a mixture of 50 parts and 50 parts of azobisisobutyronitrile was used instead of the mixture of Example 1. I got it.

Using this copolymer I, a composition (2) was prepared with the following formulation.

Copolymer (2) 31.25 parts Olestar RA-105050, 0 parts neopentyl glycol diacrylate 25. O
ibenzophenone 3.0 part 109
-25 parts (8):(C)=75:25.

This composition (2) was cured by irradiation with ultraviolet rays in the same manner as in Example 1. The properties of this coating film are shown in Table 1.

Example 5 Similarly to Example 1, an ultraviolet curable resin composition ■ was prepared using the following formulation.
was manufactured.

Copolymer (1) 8.75 parts Orestar RA-105050.00 parts Neopentyl glycol diacrylate 43.00 parts Benzophenone 3.0 parts 104.75 parts Copolymer in this formulation: (C) = 93 nia . This composition (2) was cured by irradiation with ultraviolet rays in the same manner as in Example 1.

The properties of this coating film are shown in Table 1.

Comparative Example 1 450 parts of methyl methacrylate, 4 parts of butyl acrylate
'OO part, diethylaminoethyl methacrylate] 15
Example 1 except that a mixture of 40 parts of azobisisobutyronitrile was used instead of the mixture of Example 1.
Composition (2) was prepared in the same manner as in Example 1 using the number average molecular weight.

This composition (1) was cured by irradiation with ultraviolet rays in the same manner as in Example 1. The properties of this coating film are shown in Table 1.

Comparative Example 2 550 parts of methyl methacrylate, 4 parts of butyl acrylate
Example 1 except that a mixture of 50 parts and 40 parts of azobisisobutyronitrile was used instead of the mixture of Example 1.
In the same manner as above, a copolymer M having a number average molecular weight of 3600 and a non-volatile content of 80% was obtained.

Composition (2) was prepared in the same manner as in Example 1 using this copolymer (2) as a substitute for copolymer (1).

This composition (1) was cured by irradiation with ultraviolet rays in the same manner as in Example 1. The properties of this coating film are shown in Table 1.

Comparative example 3 Composition (1) was prepared using the following formulation.

OLESTAR RA-1050 50 parts Neopentyl glycol diacrylate 50
Part Benzophenone 3 parts 103 parts Using this composition (1), it was cured by irradiation with ultraviolet rays in the same manner as in Example 1. The properties of this coating film are shown in Table 1.

Comparative example 4 Composition (1) was prepared using the following formulation.

Copolymer (V) 60.0 parts Olester RA~1050 30.0 parts Neopentyl glycol diacrylate 22.0 parts Benzophenone 3.0 parts 115 parts Using this composition (2), the same method as in Example 1 was carried out. It was cured by irradiating it with ultraviolet light.

The properties of this coating film are shown in Table 1.

(*) Use a cutter to cut lmm x 1mIn on the coating surface.
Cut the base into 100 pieces and show the seven pieces.

(**) Visually judge the condition after storage for 72 hours at 5Q℃ in a 99% humidity atmosphere.

(**'*) Immediately after the above moisture resistance deterioration, a base grain tape peeling test is performed and the number of base grains remaining in close contact with the base material is displayed.

patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Scope of Claims] A mixture of the compound (A) having at least one ethylenically unsaturated group in the molecule and a photopolymerizable sensitizer is applied to a base material, and the mixture is irradiated with ultraviolet rays. In the ultraviolet curable resin composition for forming a film, the general formula (B) (wherein R1 is a hydrogen atom or a methyl group)
are the same or different hydrogen atoms or alkyl groups, n
acrylic monomer (B) represented by (integer from 1 to 3)
0.5% by weight or more and 10% by weight or less, and 90% by weight or more of an ethylenically unsaturated monomer copolymerizable with (B)9
9.5% by weight or less The number average molecular weight obtained by copolymerization is 1
Copolymer (C) of 000 to 1oooo (A): (
C) = 95:5 to 60:40 (weight ratio). An ultraviolet curable resin composition with improved adhesion.