JPH0431476A - Adhesive for use in heat-sensitive stencil printing master paper - Google Patents

Abstract

PURPOSE:To improve curing properties, solvent resistance, printing resistance and punchability by compounding urethane diacrylate, epoxy diacrylate, polyol diacrylate, a photoreaction initiator and a tertiary amine. CONSTITUTION:100 pts.wt. urethane diacrylate obtained by reacting urethane diisocyanate and hydroxylated acrylate, 10-200 pts.wt. epoxy diacrylate obtained by reacting an epoxy compound (e.g. bisphenol A diglycidyl ether) and acrylic acid, 5-50 pts.wt. polyol diacrylate (e.g. ethylene glycol diacrylate) are compounded to give a mixture. To 100 pts.wt. said mixture are added 1-10 pts.wt. photoreaction initiator (e.g. 2-methyl-1-(4-alkylthiophenyl)-2- morpholinopropen-1-one) and 1-10 pts.wt. tertiary amine (e.g. triethanolamine) to give a adhesive having a viscosity of 100-100,000cp at 20 deg.C for use in heat- sensitive stencil printing master paper.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an adhesive used when manufacturing heat-sensitive stencil paper, and more specifically, an adhesive that is highly workable as an adhesive for manufacturing base paper, The resulting base paper has excellent perforation properties and printing resistance.

[Conventional technology]

The base paper used in thermal stencil printing is made by laminating a thermoplastic resin film such as a polyester film or a vinyl chloride resin film with a porous support such as natural fiber or chemical fiber.

The adhesive used in this case is one that can be easily applied, and the adhesive layer after manufacturing the base paper is easily perforated, and even if a large amount of printing is performed, it will not be attacked by the solvent in the printing ink. What is needed is a material with excellent printing resistance that does not reduce adhesive strength.

Conventionally, there are the following three types of adhesives used in producing base paper for thermal stencil printing.

m Adhesives dissolved in water or organic solvents (2) Reactive adhesives, room temperature curing type and thermosetting type (3)
True melt adhesive However, in the case of fi+, it is necessary to remove water and organic solvents after adhesion, and the solvent resistance after lamination (
The inks that can be used are therefore extremely limited. In particular, when water is used, a large amount of heat is required for drying, which impairs the dimensional stability of the base material, which is not preferable.

In the case of (2), even with room temperature curing type urethane adhesives, the curing speed is slow and it takes a long time to completely bond after manufacturing, which reduces productivity. It is unfavorable as it is significantly lowered.

Furthermore, the thermosetting type is undesirable because it causes shrinkage due to the effect of heat on the base material during adhesion and tends to cause curling of the product.

In the case of (3), the melting point and melting temperature are generally high, which not only makes it difficult to apply uniformly, but also because it is heated, similar to when thermosetting adhesives are used in (2). It is undesirable because it causes drawbacks.

[Problem that the invention seeks to solve]

The present invention is an adhesive that is easy to apply, can obtain sufficient adhesive strength in a short time after application, and has excellent printing durability. Therefore, when bonding porous supports such as thermoplastic resin films, productivity is significantly improved compared to using conventional adhesives.

[Means of trying to solve the problem]

In order to solve the above-mentioned drawbacks of the conventional products, the present invention is an ultraviolet curing type, and when heated to 500°C or more after coating and curing,
They achieved this goal by using an adhesive that partially decomposes and evaporates.

And, the present invention comprises: urethane diacrylate, (Bl epoxy diacrylate, fc) polyol diacrylate, ff) l photoinitiator, (El tertiary amine, fB), (C)
, fD) and (D) are the main components,
(Al: (B): C1=100=10~20
A viscosity of 100 to 100.000 CP/2 is obtained by adding 1 to 10 parts by weight of fDl to 100 parts by weight of a mixture having a ratio of 0:5 to 50, and 1 to 10 parts by weight of (D).
This is an adhesive for stencil paper with a temperature of 5°C.

Component (5) is a diisocyanate compound or a compound in which a urethane diisocyanate consisting of a diisocyanate and a glycol is reacted with a hydroxyl group-containing acrylate to form an acryloyl group at the end.

Diisocyanate compounds include aliphatic, aromatic or alicyclic compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, cyclohexane diisocyanate.・Isophorone diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, m
-phenylene diisocyanate and the like.

Examples of glycols used in the production of urethane diisocyanate include ethylene glycol, 1.2-propylene glycol, 1.3-propylene glycol, and 1.3-propylene glycol.
3-butylene glycol, 1.4-butylene glycol, 2.3-butylene glycol, 1.6-hexanesiol neopentyl glycol, hydrogenated bisphenol A, diethylene glycol, triethylene glycol, dipropylene glycol, 1.5-bentanediol, poly tetramethylene ether glycol, ethylene glycol,
Those obtained by ring-opening addition polymerization of ethylene oxide, propylene oxide, or a mixture thereof using propylene glycol as an initiator, and other polyester glycols such as maleic acid, fumaric acid, succinic acid, adipic acid, and sebacic acid. , those obtained by condensation of a dibasic acid such as phthalic acid and a dihydric alcohol.

Examples of dihydric alcohols include ethylene glycol,
Propylene glycol, diethylene glycol, dipropylene glycol, 1°3-butylene glycol, 1.
4-butylene glycol, 1,5-bentanediol,
Examples include 1,6 hexanediol, neopentyl glycol, triethylene glycol, and cyclohexanediol.

The urethane diisocyanate can be produced by a known method using the diisocyanate and glycol in a molar ratio of 2=1.

As acrylate containing hydroxyl group for acrylation,
Examples thereof include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, and monoepoxy compounds such as butyl glycidyl ether, addition reaction products of 2-ethylhexyl glycidyl ether and acrylic acid, and the like.

The addition reaction between the diisocyanate and the hydroxyl group-containing acrylate can be carried out by a known method, for example, by dropping a mixture of the hydroxyl group-containing acrylate and a catalyst such as dibutyltin dilaurate in the presence of a diisocyanate compound under conditions of 60 to 90°C. can.

Among those obtained in this way, aliphatic ones are preferred.

After curing with ultraviolet rays, these particles easily perforate the base paper by heating the base paper with a thermal head, and have particularly excellent adhesive strength with the film, so they are not easily attacked by solvents in printing ink during printing, and are highly resistant to rigidity. Demonstrates excellent effects.

The epoxy diacrylate of the +Bl component is a compound obtained by reacting an epoxy compound with acrylic acid, and has an acryloyl group at the end.

Epoxy compounds such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, novolac phenol diglycidyl ether, and polyoxyalkylene diglycidyl ether can be used.

Although the present invention does not particularly limit the structure of the epoxy compound,
From the viewpoint of perforation, polyoxyalkylene epoxy compounds are preferred.

Examples of the ten components include ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, propylene glycol diacrylate, 1-3-butylene glycol diacrylate, and 1-6-hexanediol diacrylate.

Regarding the fDl component, considering the perforability of Kawahara cotton for stencil printing, the film thickness when applying the adhesive needs to be as thin as 0.1 to 3 μm. Those that undergo reaction curing are preferred, and 2-methyl 1-(4-alkylthiophenyl)-2-morpholinopropan-1-one, thioxanthone, and the like are particularly excellent.

([:l components include aliphatic amines and aromatic amines, specifically triethanolamine, methyljetanolamine, triisopropanolamine,
Preferred are n-butylamine and N-methyljetanolamine.

The present invention has the following characteristics: (Bl:(C)=1 oo: 10
It is used at a ratio of ~200:5~50, (B
If the l component is less than 10, the viscosity of the adhesive will be high and coating will be difficult, which is not preferable. On the other hand, if it is larger than 200, the adhesiveness decreases, which is not preferable.

If the +C1 component is less than 5, the perforability of the adhesive layer will be insufficient, which is not preferable. On the other hand, if it is larger than 50, the adhesiveness will be significantly lowered, which is not preferable.

(Dl and (E) are less than 1 part by weight relative to 100 parts by weight of C1-1, which is undesirable because photocuring will not progress sufficiently. Also, if it is more than 10 parts by weight, the effect of polymerization initiation is Not only is this not improved, but the physical properties of the cured coating are deteriorated and the adhesive strength is reduced, which is not preferable.

The adhesive of the present invention preferably has a viscosity of 100 to 100,000 centipoise (B-type rotational viscometer) at 25°C; if it is less than 100, uniform application will be difficult and the film thickness will not be constant. Undesirable, ioo
, ooo, the viscosity is so high that it is difficult to apply it in a thin film.

The thermoplastic resin film to which the adhesive of the present invention is applied may be any film that can be used for thermal stencil printing.
Examples include polyester, polyvinylidene chloride, vinylidene chloride-vinyl chloride copolymer, and polyester and vinylidene chloride films are particularly excellent.

The film is preferably highly oriented or stretched.

The porous support may be any porous material that becomes substantially porous when heated and allows ink to pass through during printing, such as manila hemp, polyester fibers, non-woven fabrics, polyester fibers, and silk. Suitable examples include screen gauze and the like.

For laminating thermoplastic resin film and porous support,
The adhesive of the present invention is applied to the surface of a thermoplastic resin film at O,1
Coated with a M thickness of ~3 μ and 2 kg of porous support on top.
/aI! After crimping with a certain degree of gravity, the film is irradiated with ultraviolet rays for 0.05 seconds or more using an ultraviolet lamp with an output of 80 W/csi.

Examples and comparative examples will be described below. Note that parts by weight are abbreviated as parts.

Example 1 As a carrier component, isophorone diisocyanate (IPDI) 2 was added to 1 mol of a polyester diol with molecules ill 000 consisting of 1.6-hexane diol and adipic acid.
35 parts of urethane diacrylate synthesized from 1 mole of urethane diisocyanate produced by addition reaction of 2 moles and 2 moles of 2-hydroxypropyl acrylate, component (B) synthesized from 1 mole of bisphenol A, 2 moles of epichlorohydrin, and 2 moles of acrylic acid. 55 parts of epoxy diacrylate, fc) component: 10 parts of polyethylene glycol 200 cyacrylate, 4 parts of fil diethylthioxanthone + EI
N-Methyldiethanolamine 4 parts or more, ~ (E
) and has a viscosity of 8000CP.
/25°C to obtain the adhesive of the present invention.

In addition, in the ratio of prisoner: f8): (Cn-100160:30, [factor 18) + (C1): fDl
: (E)-100:4:4.

The adhesive was applied to the surface of a 2μ thick polyester film using a roll coater in an amount of Ig/rrr, and then a porous support (manilla linen thin paper, 8.5g/rrr)
) was crimped. Thereafter, the adhesive of the present invention was cured by irradiating ultraviolet rays with an ultraviolet irradiation device, and the film and support were bonded together.

Next, an NJ release agent prepared by mixing silicone resin and silicone oil in Step 11 was applied to the film surface of this base paper using a roll coater.

When the heat-sensitive stencil paper prepared as described above was subjected to stencil printing using a digital stencil printing machine (manufactured by Riso Kagaku Kogyo Co., Ltd., RISOGRAPH O0, 7DIllN) using a thermal head, a good printed image was obtained. Ta. The following measurements were also carried out and the results are shown in Table 1.

(b) Printing durability Visual evaluation of the 1000th printed image after the start of printing.

Evaluation of printed images Visual evaluation of the appearance of printed images Example 2 The causal components were 1 mol of polyoxypropylenated bisphenol A (ADEKA BPX-33 manufactured by Asahi Denka ■) and IPD.
1 mol of urethane diisocyanate produced by addition reaction of 2 mol of I, and 2-hydroxypropyl acrylate 2
40 parts of urethane diacrylate synthesized from moles fBl component: 50 parts of epoxy diacrylate synthesized from polyoxypropylenated bisphenol A, epichlorohydrin and acrylic acid (C) 10 parts of polyethylene glycol 400 diacrylate, (D) 2-methyl- 1-(4-methylthiophenyl)-
4 parts of 2-morpholinopropan-1-one (4 parts or more of F3N-methyljetanolamine,
~ (It is a combination of 5 ingredients and has a viscosity of 150
00CP/25°C adhesive of the present invention is obtained.

Furthermore, prisoner:(B):1cl=100:125:25, [prison+(B11(cl):(Dl:fE)=1
00:4:4.

Thereafter, the same operations as in Example 1 were performed, and the results are shown in Table 1.

Example 3 2-hydroxypropyl acrylate 2 as a prisoner component
50 parts of urethane diacrylate synthesized from 1 mole of hexamethylene diisocyanate and 1 mole of tripropylene glycol as the tBl component,
30 parts of epoxy diacrylate synthesized from 2 moles of epichlorohydrin and 2 moles of acrylic acid, (C) 20 parts of polyethylene glycol 200 diacrylate, 10) 3 parts of diethylthioxane phosphorus, fE) 3 parts of N-methyljetanolamine, The above is a mixture of 5 components of El ~ (El), and the viscosity is 2000CP/25℃
The adhesive of the present invention is obtained.

In addition, prisoner: fBl: C)) = 100:60:40,
[Prison→−(Bl + IcI) −(Dl F +
Day = 100:3:3.

Thereafter, the same operations as in Example 1 were performed, and the results are shown in Table 1.

Comparative Example 1 In Example 1, ^: fBl: C1=100:
The same operation as in Example 1 is performed except that the time is 5:45.

Comparative Example 2 In Example 1, CA):(R1:fc)=100:220
:30, the same operation as in Example 1 is performed.

Comparative Example 3 In Example 1, prisoner: fBl: (C) = 100: 14
The same operation as in Example 1 is performed except that the ratio is 6:2.

Comparative Example 4 In Example 1, prisoners: TR1: (C) = 100: 90
:60, the same operation as in Example 1 is performed.

Table *Comparative Example 3: Coating was uneven and printing durability could not be measured.

〔Effect of the invention〕

B) Since the viscosity of the adhesive can be set low, uniform thin W
A thickness of a is obtained.

(Foundation) The adhesive quickly cures when exposed to ultraviolet rays, which significantly improves productivity. (C) Due to the high crosslinking density after curing, it has excellent solvent resistance and significantly improves printing durability. do.

B) After coating and curing, it has the property of partially decomposing and vaporizing when heated to 500° C. or higher, and therefore has excellent perforation properties and produces printed matter with sharp images.

Claims (1)

[Scope of Claims] (A) urethane diacrylate, (B) epoxy diacrylate, (C) polyol diacrylate, (D) photoinitiator, (E) tertiary amine, (A) and (B) ), (C), (D) and (E) 5
The main component is (A):(B):(C
) = 100:10 to 200:5 to 50 parts by weight of a mixture, 1 to 10 parts by weight of (D), and (
The viscosity obtained by blending 1 to 10 parts by weight of E) is 100 to 10
0.000CP/25℃ adhesive for heat-sensitive stencil paper.