JPH01275615A - Ionizing radiation-curable solventless pressure-sensitive adhesive composition - Google Patents

Abstract

PURPOSE:To obtain a pressure-sensitive adhesive of excellent water resistance and high-temperature properties, by using a specified radical-polymerizable double bond-containing polyester. CONSTITUTION:The title pressure-sensitive adhesive composition comprises 100pts.wt. radical-polymerizable double bond-containing polyester (a) formed by reacting the carboxyl groups on the terminals and/or side chains of a polyester obtained by reacting a polyester comprising an at least trifunctional polycarboxylic acid with a polyol with a radical-polymerizable double bond- containing monomer, 0-200pts.wt. tackifying resin (b), and 0-15pts.wt. sensitizer (c). The polyester (a) is a fluid viscous at room temperature and, if necessary, a tackifier, a sensitizer, etc., are added thereto. The obtained mixture is applied to a substrate, and its cohesive force is increased by irradiation with an ionizing radiation to form a pressure-sensitive adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ionizing radiation curable solventless pressure sensitive adhesive composition.

Conventional pressure-sensitive adhesive composition C2 is rubber-based, acrylic-based,
There are vinyl ether type, silicon type, etc.

These are so-called solvent-based pressure-sensitive adhesives that generally use organic solvents. However, in recent years, from the standpoint of resource and energy conservation, pollution, fire, and environmental hygiene, there is a trend towards solvent removal, and emulsion type pressure sensitive adhesives and hot melt type pressure sensitive adhesives have been developed. However, emulsion-type pressure-sensitive adhesives require a large amount of energy to dry and have the disadvantage of poor water resistance. In addition, hot-melt pressure-sensitive adhesives not only require a large amount of thermal energy to be melted to a viscosity that can be coated, but also have the disadvantage of poor high-temperature properties.

The present invention was achieved as a result of intensive research by the present inventors in order to solve the above-mentioned problems.

That is, 1 the present invention is a polyester (obtained by adding an aliphatic alcohol having 2 to 16 carbon atoms) consisting of a trifunctional or higher-functional polycarboxylic acid and a polyol. Water resistance and high temperature properties (double ionizing radiation A curable solvent-free pressure-sensitive adhesive composition is provided.

The pressure-sensitive adhesive composition of the present invention achieves a glass transition by adding an aliphatic alcohol to the carboxyl group that does not participate in the condensation polymerization of an ester oligomer consisting of a trifunctional or higher-functional polycarboxylic acid and a polyol to achieve internal plasticization. It was discovered that the temperature could be lowered and pressure-sensitive adhesiveness could be imparted.
In addition, a radically polymerizable double bond is added to the carboxyl group at the terminal and/or side chain, and the radically polymerizable double bond is further reacted by irradiating the radically polymerizable double bond with ionizing radiation such as ultraviolet rays or electron beams. It was invented after discovering that cohesive force can be further improved.

Examples of trifunctional or higher-functional polycarboxylic acids used in the present invention include trimellitic acid, citric acid, tricarbanic acid, and pyromellitic acid.

Examples of polyols include ethylene glycols such as ethylene glycol, diethylene glycol, and triethylene glycol, propylene glycols such as propylene glycol, dipropylene glycol, and tripropylene glycol, hecoptanediol, /, couptanediol, bentanediol, and conityl. 1. Aliphatic diols such as 3-hexanediol, 2-ethyl/, 6-hexanediol, heptanediol, /, two-octanediol, /, male-octanediol, and nonanediol, or their isomer diols. . It also has an acid component.”
An aliphatic dicarboxylic acid or an aromatic dicarboxylic acid may be added within a range of ctomolti or less. Examples of aliphatic dicarboxylic acids include succinic acid, glutaric acid, adipic acid, pimelic acid, superric acid, azelaic acid, sepacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, onedecanedicarboxylic acid, dodecanedicarboxylic acid or its acid anhydride. can be mentioned. Examples of aromatic dicarboxylic acids include terephthalic acid and isophthalic acid. These polycarboxylic acids, polyols, and dicarboxylic acids may be used in one type or in a mixture of two or more types.

The method for synthesizing polyester consisting of polycarboxylic acid and polyol in the present invention (: Special C) is not limited and can be synthesized by any known ordinary method, but the polymerization temperature is ♂O ℃~ to prevent gelation. The temperature is preferably within the range of 150°C.It is not necessary to use a catalyst during polymerization, but if used, alkali metals/alkaline earth metals and their oxides, weak acid salts, titanate esters, germanium oxide,
Acetate, titanium compounds, antimony compounds, etc. are used.

Further 1: The polyester obtained in this way is internally plasticized by adding an aliphatic alcohol to the carboxyl group in the molecule or at the end of the polyester to lower the glass transition temperature and improve pressure-sensitive adhesive properties. However, this polyester C; has unreacted carboxyl groups as described below! It must contain more than mol and less than 20 mol.

Also, the amount of carboxyl groups added is J-
If the molar ratio is less than 3, the glass transition temperature will not be lowered even if the aliphatic alcohol is added, and pressure-sensitive adhesive properties will not be developed.

The aliphatic alcohol used for addition to the polyester is one having 16 carbon atoms, preferably an aliphatic alcohol having q to //// carbon atoms. When the number of carbon atoms is /, the glass transition point is not lowered sufficiently and pressure sensitive adhesiveness is not developed. Further, when the number of carbon atoms is 72 or more, the formed oligomer crystallizes. The addition reaction temperature is preferably 100° C. or higher, and in this case, p-toluenesulfonic acid or the like is used as an esterification catalyst, but it may or may not be used. Moreover, since the polyester obtained by C: has fluidity at room temperature and lacks cohesive force, a radically polymerizable double bond gold-containing hexamer is reacted with the molecular chain terminal or molecular side chain of the polyester. In this way, a radically polymerizable double bond-containing polyester (unsaturated group-containing polyester) is obtained.

In this case, the acid component! It is necessary to unsaturate the mole fraction or more and less than λθ molar coefficient. If it is less than jmolti, the cohesive force will not improve. If the molar ratio is more than 20, the crosslinking density becomes too high,
Pressure-sensitive adhesive properties are lost.

The above-mentioned radically polymerizable double-bond gold-containing monomer may be any monomer having a functional group that reacts with a carboxyl group, such as glycidyl (meth)acrylate, isocyanate methyl (meth)acrylate, isocyanate ethyl (meth)acrylate, Isocyanate propyl(meth)acrylate), 2-(/-aziridinyl)ethyl(meth)acrylate), J-(/-(,2methylaziridinyl))ethyl(meth)acrylate, and the like.

Further, an equimolar reaction product of a hydroxyl group- or carboxyl group-containing monomer and a diisocyanate can also be used. Examples of hydroxyl group-containing monomers include cohydrooxyvethyl (meth)acrylate, cohydropropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate, and examples of carboxyl group-containing monomers include (meth)acrylic acid. Can be mentioned. As the diisocyanate, /, 6 hequinamethylene diisocyanate).

Toluylene diisocyanate, xylylene diisocyanate, metaphenylene diylene anate, diphenylmethane diisocyanate, naphthalene diisocyanate,
Examples include inphorone diisocyanate.

The radically polymerizable double bond-containing polyester obtained in this way is a viscous fluid at room temperature, and if necessary, a tackifying resin, a sensitizer, etc. are mixed therein, and the base material (: coating After that, ionizing radiation is irradiated to improve the cohesive force,
Use pressure sensitive adhesive.

Examples of tackifier resins include rosin resins, terpene resins, aliphatic petroleum resins, aromatic petroleum resins, alicyclic petroleum resins, coumaron resins, styrene resins, alkylphenol resins, and xylene resins. There are cases where it is not necessary to add the tackifier resin, but if it is necessary to add it, adding 200 parts or more will eliminate tack. The preferred amount to be added may be determined as appropriate depending on the application, but from 410 to
/j0 parts by weight is often preferred. Also anti-aging agent,
Fillers, colorants, etc. can also be added as appropriate.

Examples of the substrate to be coated include paper, cloth, nonwoven fabric, plastic film, cellophane, and the like.

Examples of ionizing radiation include ultraviolet rays and electron beams.

In the case of ultraviolet irradiation, a sensitizer must be added, and examples of the sensitizer include benzoin isobutyl ether, benzoin isopropyl ether, benzoin ethyl ether, benzoin methyl ether, /phenyl/, 2
7” lopanedione-2(0-ethoxycarbonyl)oxime, 2.2-dimethoxy-2-phenyl-acedobuenone, hydroxycyclohexyl phenyl ketone, jetoxyacetophenone, 2-hydroxy-2-methyl-1 phenylpropane-1, benzophenone, benzyl , methyl-〇benzoin benzoate, 200-thioquinanthone, isopropylthioxanthone, 2-methylthioxanthone, and the like.

The amount added is 03~/! It is a cloud.

Next (=Example will be explained.

First, (a) an example of synthesis of polyester, and (b) an example of addition reaction of an aliphatic alcohol to polyester (including an example of synthesis of unsaturated polyester) will be described. In addition, the number average molecular weight listed below (: is the polystyrene equivalent value according to GPC (:), the acid value is the η number of potassium hydroxide required to neutralize the sample /, and the Tg (glass transition temperature) is the Seiko The value is based on a DSC measuring device (manufactured by Denshi Kogyo Co., Ltd.).The addition rate was determined from the acid value values before and after the reaction.

[Example of polyester synthesis]

(a-t) citric acid t9,. 2 t (tθ0 molar ratio) propylene glycol 749 was put into a Yotsuro flask, and 100 to 14
The reaction was carried out for 6 hours while removing moisture at a temperature of 0°C.

The number average molecular weight of the product is gθ0θ, the acid value is 2/l, and Tg
was 2/°C.

(, a-2') Citric acid /34Itt (7o mol)
Adipic acid 4t4tt (30mopy4
) Propylene glycol 76? were reacted in the same manner as in Synthesis Examples No.-a. The number average molecular weight of the product was too, the acid value was /4θ, and the Tg was -3°C.

Ca-3> Citric acid 9. gr (jθ molar ratio)
Adipic acid? f (jθ molar ratio) Propylene glycol 76f was reacted in the same manner as in Synthesis Example/-5-=a. The number average molecular weight of the product is jooo, the acid value is /22, and the Tg is 17! It was ℃.

(a-4t) Tricarbanilic acid 12g? Chitin diol/4ttt was added to λ ethyl 7.3 in a Yotsuro flask and heated at 120 to 110°C in a nitrogen stream.
The reaction was carried out at a temperature of 3 hours while removing moisture.

Product number average molecular weight too, acid value 07, T121
It was ℃.

[Example of addition reaction of aliphatic alcohol to polyester]

(b-/) Yotsuro flask C2 synthesis example a-/ (polyester (oligomer) produced from 2!001 and methanol (
The number of carbon atoms/)/jr was added, p-toluenesulfonic acid was added as a catalyst at θ,/f, and 24 was reacted at the boiling point of methanol for 24 hours to obtain an aliphatic alcohol addition polyester (hereinafter abbreviated as addition polyester). The addition rate and Tg of the obtained addition polyester were -//'C.

Furthermore, glycidyl methacrylate ♂f and triethylamine/f were added to the obtained addition polyester,
At 20℃/! The mixture was reacted for a period of time to obtain a radically polymerizable double bond-containing polyester (hereinafter referred to as unsaturated group-containing polyester).

(b-2) Polyester 1001 of Synthesis Example a-/ and conitylhexyl alcohol (carbon number z) sit were added to the same apparatus as in Addition Reaction Example b-/, and p-toluenesulfonic acid 0.0% was added as a catalyst. / f woka L/! The reaction was carried out at 0 to 10°C for 2 hours to obtain an addition polyester. The addition rate/4tl and Tg of this addition polyester were -j/C.

Furthermore, glycidyl methacrylate ♂, rit and triethylamine lt were added to the obtained addition polyester,
The reaction was carried out at 10° C. for 7 t hours to obtain an unsaturated group-containing polyester.

(b-j) Oligomer/θθt of Synthesis Example a-/ and heptadecanol (carbon number/2) were added to the same apparatus as in Addition Reaction Example b-/, and p-toluenesulfonic acid θ and p-toluenesulfonic acid θ were added as catalysts.
/f was added and reacted for 1 hour at /J'0~/♂θ°C, to obtain an addition polyester crystal with an addition rate of 70%.

(b-4t) In the same apparatus as in addition reaction example b-7, polyester 1001 of synthesis example a-2 and 1,2 ethylhexyl alcohol (carbon number/?) were added. 7f and 0.7f of p-toluenesulfonic acid as a catalyst. Add /f and l! The reaction was carried out at θ°C to 1/θ°C for 2 hours to obtain an addition polyester having an addition rate of 11% and a Tg of -4trC.

Further C2, this obtained addition polyester II/(niglycidyl notacrylate, 7 t and triethylamine/l
was added and reacted at 20°C for /j hours to obtain an unsaturated group-containing polyester.

<b-, t> Apparatus similar to addition reaction example b-/ (adding polyester/θ01 of synthesis example a-3 and conitylhexyl alcohol (carbon number ♂) 21f, p-toluenesulfonic acid θ as a catalyst, /fwo processing/j"θ~/♂ Reaction was carried out for 2 hours at 0°C to obtain an addition polyester with an addition rate ♂/'A%Tg of -3♂°C.

Further C2, add glycidyl methacrylate, trit, and triethylamine/l to this addition polyester, and heat to ♂θ℃.
The reaction was carried out for 7 t hours to obtain an unsaturated group-containing polyester.

(b-j) In a device similar to Addition Reaction Example b-/, 100f of the polyester of Synthesis Example a-da and butyl alcohol (carbon number 4t) were added.
) J♂f and catalyst (2p toluenesulfonic acid 0.
/f was added and reacted for 6 hours at 10J'' to /10°C, resulting in an addition rate of 69J and Tg-44/°C.

Calibration: Glycidyl methacrylate/lf and triethylamine/f were added and reacted at 20°C for 73 hours to obtain an unsaturated group-containing polyester.

(b-7) Using the same apparatus as Addition Reaction Example b-/(2. Synthesis Example a-g) polyester 10θf and hexyl alcohol (carbon number 4>3st) were added and heated at around 740°C without using any catalyst. When the reaction was carried out for a certain period of time, the addition rate J'1%, Tg-j/
It became C.

Further (=glycidyl methacrylate)/? f and triethylamine/f were added and reacted at 20°C for 73 hours to obtain an unsaturated group-containing polyester.

(b-♂) Apparatus C similar to addition reaction example b-/: polyester lθ0t of synthesis example a-7 and nonyl alcohol (carbon number 9)
101 and p-toluenesulfonic acid 0.1 to the catalyst. /f
was added and reacted at 120 to 130°C for 7 hours, resulting in an addition rate of 014 and a Tg of -47°C.

Furthermore, glycidyl methacrylate (J, 4 t) and triethylamine/2 were added and reacted at 20°C for 73 hours to obtain an unsaturated group-containing polyester.

〔Example/〕

Addition reaction example 1 λ unsaturated group-containing polyester 100 parts by weight DA parts by weight Ul/7j (manufactured by Merck & Co.)
3 g were melt-mixed at 20°C, coated on a polyester film (Lumirror #2j manufactured by Toshi Co., Ltd.) to a thickness of Jjμ, and heated under a high-pressure mercury lamp of ♂0° at a distance on the θ side. A pressure-sensitive adhesive sheet was obtained by irradiating ultraviolet rays at a speed similar to that of the original.

[Example]

Addition reaction example b -, 2 unsaturated group-containing polyester 100 parts by weight ys Polyster T-//j (manufactured by Cheap Oil) ♂0IDA
ROCUR/173 (manufactured by Merck & Co.) J″
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example I.

[Example 3] Addition reaction example b-g unsaturated group-containing polyester ioo parts by weight YS Polyster T-//! (made by cheap crude oil) 101 DAR
OCURz/7j (manufactured by Merck & Co.) j2
C2 was carried out in the same manner as in Example 1 to obtain a pressure-sensitive adhesive sheet.

[Example G]

Unsaturated group-containing polyester of addition reaction example b-4 lθθ parts by weight Ester gum HP (manufactured by Arayo Kagaku Kogyo Co., Ltd.) ♂0I Irga ￥ Near 6! / (manufactured by Ciba Geigy) 31 was prepared in the same manner as in Example / to obtain a pressure-sensitive adhesive sheet.

[Example j]

Addition reaction example b -7 unsaturated group-containing polyester 100 parts Ester gum HP (manufactured by Arayo Kagaku Kogyo Co., Ltd.) ♂0I Irgacure 6ta/(manufactured by Ciba Geigy Co., Ltd.) 3 g
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1.

[Example 6] Addition reaction example 1 ♂ unsaturated group-containing polyester ioo part ester gum HP (manufactured by Arayo Kagaku Kogyo Co., Ltd.) ♂ Ql Irgacure 61/ (manufactured by Ciba Geigy) 3z was added in the same manner as in Example 1 (= A pressure-sensitive adhesive sheet was obtained.

[Comparative example/]

Addition reaction example b-/Unsaturated group-containing polyester obtained from (addition polyester added with aliphatic alcohol (C=/)) 100 parts by weight YS Polyster T-its (manufactured by Chess Oil) ♂0IDAROCUR
y17j (manufactured by Merck & Co., Ltd.) zg was prepared in the same manner as in Example 1 to obtain a pressure-sensitive adhesive sheet.

[Comparative example]

The oligomer of addition reaction example b-3 was crystalline and did not become a pressure-sensitive adhesive.

[Comparative Example 3] 100 parts by weight of the unsaturated group-containing polyester of addition reaction example b-3 YS Polyster T-//j (manufactured by Cheap Oil) ♂QI
DAROCUR1123 (manufactured by Merck & Co.)
A pressure-sensitive adhesive sheet was obtained using 2g of the product in the same manner as in Example.

Adhesive strength of pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples,
The water resistance and high temperature characteristics are shown in the table below.

(Left below) #l Adhesive force measuring equipment Instron type tensile tester Sample width
Ko! ■ Tensile speed 300 degrees Measurement conditions 23°C Humidity tt Peeling 7♂0 degree peeling Adherent Stainless steel plate #2 Water resistance Immersed in 410°C ion-exchanged water for 10 hours and observed changes.

#3 High temperature characteristics Ko! ■X2! / at 20℃ with an area of m
Measurement of deviation distance of Kt load As described above, according to the present invention, without using an organic solvent,
Moreover, a pressure-sensitive adhesive tape with excellent water resistance and high-temperature properties I can be obtained without using a large amount of melting energy.

Claims (1)

[Scope of Claims] 1a. A carboxyl group at the terminal and/or side chain of a polyester obtained by reacting a polyester consisting of a trifunctional or higher functional polycarboxylic acid and a polyol with an aliphatic alcohol having 2 to 16 carbon atoms. It is characterized by containing 100 parts by weight of a radically polymerizable double bond-containing polyester (b) reacted with a radically polymerizable double bond-containing monomer, 0 to 200 parts by weight of a tackifying resin (c), and 0 to 15 parts by weight of a sensitizer. An ionizing radiation-curable solvent-free pressure-sensitive adhesive composition. 2. The ionizing radiation-curable solvent-free pressure-sensitive adhesive composition according to claim 1, wherein the trifunctional or higher-functional polycarboxylic acid contains 40 mol% or less of dicarboxylic acid.