JPS61281173A - Dispersion liquid of adhesive granule suspended in solvent and pressure-sensitive adhesive tape utilizing characteristic thereof - Google Patents

Abstract

PURPOSE:To provide the titled dispersion liquid composed of internally crosslinked fine particle of pressure-sensitive adhesive obtained by the copolymerization of specific monomers, a binder consisting of a styrene- containing polymer having small particle size and an organic solvent and leaving no residual adhesive particles on an adherend after peeling off a pressure- sensitive adhesive sheet. CONSTITUTION:The objective dispersion liquid is composed of (A) 100pts.(wt.) of internally crosslinked pressure-sensitive adhesive particles having particle diameter of 5-200mu and obtained by copolymerizing (i) 2-10(wt)% methyl acrylate and/or styrene and/or methacrylate of 1-5C alcohol, (ii) 98-90% acrylate of 2-12C alcohol and/or methacrylate of 6-12C alcohol, (iii) 0.1-2% maleic anhydride and (iv) 0.05-1% tetraallyloxyethane or triallyl (iso)cyanate, (B) 2-20pts. of styrene-containing polymer having a styrene content of 5-70% and particle diameter of 0.02-3mu and acting as a binder of the particle A and (C) an organic solvent.

Description

[Detailed description of the invention] This invention relates to a pressure-sensitive adhesive sheet that utilizes adhesive properties.

More specifically, when a pressure-sensitive adhesive sheet is attached to an adherend and then peeled off, adhesive particles migrate to the adherend (residual adhesive).
Very few things to do 1 This relates to a solvent-suspended adhesive granule dispersion for making a pressure-sensitive adhesive sheet, and a pressure-sensitive adhesive sheet made using the dispersion.

In recent years, adhesive granules have been lined up and adhered to the surface of a sheet-like substrate, such as paper, and the side of the paper where the adhesive granules are lined up is pasted to another adhered surface, then peeled off, and then pasted again. There are office supplies that can repeat the '8y peeling action of releasing again.

This takes advantage of the characteristics of sticky granules with particle diameters ranging from several microns to hundreds of microns. In other words, granular sticky resin is lined up on the surface of the paper like an octopus's suckers. When that surface comes into contact with another adhered surface, bonding occurs at the undefeated point and both surfaces adhere. Then, when both sides are peeled off, the point-adhesive part is peeled off, leaving the adhesive granules exposed and ready to be reattached to the adherend. Such paper that can be repeatedly peeled off can be obtained by applying a dispersion of adhesive granules to the paper.

In this case, it is preferable that adhesive particles having an average particle diameter of several microns to several hundred microns are closely arranged on the surface of the paper.

In addition, it is preferable that the adhesive particle shape is as truly spherical as possible. If the paper is crushed like a rugby ball, it becomes close to surface bonding, and the adhesive strength becomes strong, causing peeling between paper wastes (paper peeling).

Also, it is better for the particle size distribution to be as narrow as possible. Because only large particles selectively participate in adhesion,
This is because the adhesive force is weak and it is not practical6. By the way, this type of adhesive granules that have been known in the past are
It is produced by suspension polymerizing acrylic monomers in water using an oil-soluble polymerization initiator, but this aqueous suspension of sticky granules poses problems when applied to non-water-absorbing substrates. However, if applied directly to paper, the paper will curl due to moisture, significantly reducing its commercial value, so water, which is the solvent for an aqueous suspension, is usually replaced with toluene, ethyl acetate, or
, 1.1-) Substituted with a solvent such as dichloroethane and applied to paper as a solvent-based dispersion. Furthermore, the use of a solvent-based material has the advantage that it has a faster drying rate than a water-based material and has extremely good mechanical stability.

However, with conventionally used resins, even if a poor solvent with low affinity is selected, there is a tendency for m-lipid II hydration to occur, to varying degrees, and adhesive granules to fuse and form a film. As shown, surface adhesion occurs with other adhered surfaces, and when peeled off, paper layer peeling occurs, resulting in poor re-adhesion.

The present inventor has considered internally crosslinking the adhesive resin in order to make it resistant to swelling in solvents and to provide appropriate adhesive performance.

In addition, certain internally crosslinking monomers, such as tetra7lyloxyethane, triallyl cyanurate, and triallyl isocyanurate, are highly reactive and uniformly internally crosslink the acrylic polymer, so that water in the suspending medium Aqueous suspensions of perfectly spherical sticky granules with uniform particles that do not swell or dissolve even when replaced with a solvent, and solvent-suspended sticky granules and sensations using them. He invented a pressure-sensitive adhesive sheet, which he previously filed as Japanese Patent Application No. 59-271305 and No. 59-271306.

This invention is an invention that exhibits extremely excellent adhesive properties. As a result of further research into this invention, the present inventors succeeded in further improving the bond between the adhesive granules and the base sheet.

That is, as a result of extensive research using various types of baingu such as solvent-based resins, water-soluble resins, and water-dispersible resins in order to firmly bond the adhesive granules to the base sheet, it was found that baingu made of a polymer containing styrene was used. By filling the spaces between the adhesive particles arranged on the base sheet and bonding the adhesive particles to each other, the adhesive particles and the base sheet are bonded together. He succeeded in making it bigger.

That is, the present invention provides (A) (a) methyl acrylate and/or styrene and/or 1 to 5 carbon atoms;
7 tacrylate of alcohol 2-10! IX'! 1
% M) 7 acrylates of alcohols with 2 to 12 carbon atoms and/or 7 acrylates of alcohols with carbon numbers 2 to 12 and/or 98-90 fifi% (c) M*
v Leic acid 0.1 to 2.0% by weight (d) One or more selected from tetraallyloxyethane, triallyl cyanurate, and triallyl isocyanurate 0.
05~1.0! ! 100 parts by weight of internally crosslinked adhesive particles with a particle diameter of 5 to Zoo microns obtained by copolymerizing 1% (B) A styrene-containing polymer with a styrene content of 5 to 70% by weight, with a particle diameter of 0.02 to 2 to 20 parts by weight of sticky granules having a particle diameter of 3 microns (solid content: K), (c) a solvent-suspended adhesive granule dispersion consisting of an organic solvent, and disposed on the surface of a sheet-like substrate. <a>
, ■), (6) are copolymerized and internally crosslinked and have a particle size of 5 to 200 microns, and the spaces between the adhesive particles are filled and bonded, and the adhesive particles are attached to a base sheet. A styrene-containing polymer having a styrene content of 5 to 70% by weight, having a particle size of 0.02 to 3 microns, and comprising 2 to 20 fi 1% of bindu to the adhesive granules. It is a pressure adhesive sheet.

The positive transition temperature (Tg) of the methyl acrylate homopolymer shown in item (a) used in the present invention is 8°C.

In addition, methacrylates of alcohols having 1 to 5 carbon atoms include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and pentyl methacrylate, and each homopolymer Tg
are respectively 105℃, 66℃, 35℃, 21℃, 1
It is 0°C.

Further, T of the styrene homopolymer is 100°C.

That is, all of the monomers shown in item <a> have a homopolymer Tg of 0°C or more and around 100°C.

In addition, the 7-acrylate of furfur having 2 to 12 carbon atoms and/or the methacrylate of alcohol having 6 to 12 carbon atoms shown in item (b) is ethyl acrylate (Tg=
-22℃), butyl 7 acrylate (Tg=-52℃)
, 2-ethylhexyl 7-acrylate (Tg= -70℃
), hexyl methacrylate) (Tg = -5°C), etc. The monomers shown in section (b) all have a homopolymer T of less than 0°C minus several tens of degrees. It is something.

2 to 10% by weight of the monomer in section (a) and 9% by weight of the monomer in section (b)
The reason why 1% of 8 to 9021i is used is to essentially impart adhesive properties to the resulting resin. Outside this range, adhesive resistance cannot be improved.

The maleic anhydride in item (c) is 0.1 to 2. Ofi amount%
This is used in order to carry out the polymerization reaction smoothly and obtain stable @liIm.

(Tetraallyloxyethane in term 0 is It is shown by the structural formula, triallyl cyanurate is 0-CH,-CHHCCl It is shown by the structural formula 3, triallyl isocyanurate is C1,-CIl-CI! ! It is shown by the structural formula:

Compared to ordinary internal crosslinking agents, it has 3 to 4 polymerizable functional groups.
It is believed that the reactivity is extremely high because of the proprietary nature of the compound, which results in uniform internal crosslinking.

These may be used alone or in combination.

The amount used is suitably 0.05 to 1.0% by weight.

If it is less than 0.05% by weight, the internal crosslinking effect is small, so
Solvent resistance is insufficient, and if it exceeds 1.0% by weight, crosslinking progresses too much and adhesive performance deteriorates, which is not preferable.

In the present invention, other monomers such as N-methylol acrylamide, 7-crylonitrile, ethylene, vinyl chloride, vinyl acetate, Beopa (trade name of vinyl ester manufactured by Shell Chemical Co., Ltd.) are added in amounts that do not impair adhesive performance. 10 weight%
Can be used together within the following range.

As a method for producing the adhesive granules (A) used in the present invention, a known suspension polymerization method is used.

Examples include a polymerization method by bulk charging, a monomer dropwise polymerization method, and an emulsified monomer dropwise polymerization method.

Examples of the polymerization initiator include benzoyl peroxide, azobisine butyronitrile, tert-butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxynocarbonate, di-n-propyl peroxyfucarbonate, and tert-butyl peroxybenzoate. -ethoxyethyl) peroxycarbonate, tert-butylperoxyneodecanoate, tert-butylperoxypiparate, cy(3,5,5-trimethylhex/yl)peroxide, nolauroyl peroxide, tupropionyl peroxide Oil-soluble initiators such as Otoside, diacetyl peroxide, etc. are used.

As the suspension stabilizer, water-soluble polymers such as polyvinyl alcohol, hydroxyethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, carboxymethylcellulose, and carboxy-modified polyacrylamide are used.

Moreover, a 7-ionic surfactant and a nonionic surfactant can be used in combination. In particular, in order to stably produce an aqueous suspension, it is preferable to use a large amount of anionic surfactant.

In this way, an aqueous suspension of sticky granules is obtained, the particle size of which is suitably in the range of 5 microns to Zoo microns.

Next, the binder (B) used in the present invention has a particle size of 0.
It is a styrene-containing copolymer with a styrene content of 02 to 3 microns and a styrene content of 5 to 70% by weight. This is a binder for bonding internally porous adhesive particles (^) with a particle diameter of 5 to 200 microns to a substrate, but in order to manufacture this binder (B), α, β olefins other than styrene must be used. (meth)acrylates such as methyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethyl hequinyl acrylate, nonyl acrylate, vinyl acetate, beoba(
Shell Chemical products) such as vinyl esters, ethylene,
One or more selected from vinyl chloride, 7-acrylonitrile, butadiene, etc., and a, β-unsaturated carboxylic acid, acrylamide, N-methylolacrylamide, hydroxyalkyl 7-acrylate, glycitul 7-acrylate, divinylbenzene, tri- A mixed monomer containing a functional or crosslinkable monomer such as allyl isocyanurate or te)raallyloxyethane is used at 30 to 90%.
When 5% by weight of styrene and 5 to 70% by weight of styrene are polymerized by a known polymerization method, it is obtained in an emulsified state in water.

Known polymerization methods include, for example, a polymerization method using bulk charging;
Examples include monomer dropwise polymerization, emulsion monomer FJK dropwise polymerization, and multistage polymerization.

As the polymerization initiator, the aforementioned oil-soluble initiators can also be used, but usually water-soluble initiators such as potassium persulfate, ammonium persulfate, hydrogen peroxide, and combinations of peroxides and reducing agents, such as A redox initiator consisting of ammonium persulfate and hexathorium hydrogen sulfite is used.

Examples of emulsifiers include 7-ionic surfactants such as sodium lauryl sulfate, dodecylbenzenesulfonic acid sorg, polyoxyethylene/nylphenyl ether sulfate, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene and A nonionic surfactant such as a block copolymer of oxypropylene or a water-soluble polymeric protective colloid such as polyvinyl alcohol or hydroxyethyl cellulose is appropriately used.

The particle size of the emulsion polymer obtained by the above method is about 3 microns to about 0.02 microns, and in the present invention, particles within this range are used, but among them, about 0.1 microns.
Fine particle diameters from microns to about 0.02 microns have extremely excellent baingu effects.

To obtain a polymer emulsion with such a fine particle size, Japanese Patent Application Laid-open No. 5
The method disclosed in No. 2-72795 is used.

That is, the above-mentioned mixed monomer or mixed monomer emulsion is simultaneously added together with a polymerization initiator into an aqueous liquid containing an anionic emulsifier to perform fL(is polymerization), and the final solid content of the polymer emulsion is It can also be obtained by controlling the amount of carboxylic acid so that it does not exceed 45% by weight.Also, it can be obtained by preparing a polymer emulsion into which unsaturated carboxylic acid has been introduced and neutralizing part or all of the acid groups with an alkali. .

If the styrene content in the styrene-containing copolymer that is the binder (B) is less than 5% by weight, it will be solubilized in alcohol, resulting in a large runoff loss in the next step of pouring it into methanol and condensing it. On the other hand, if it exceeds 70% by weight, the resin becomes too hard, the adhesive force decreases, and the bonding effect between the adhesive granules and the base sheet deteriorates.

The solvent-suspended adhesive granule dispersion of the present invention is a suspension of adhesive granules (^) with internal cavities of 5 to 200 microns in particle size, obtained as described above, and a styrene content of 5 to 200 microns. 7
01!1%, emulsion of styrene-containing polymer (B) with a particle size of 0.02 to 3 microns at a solid content ratio of 100 parts by weight:
Mix in a ratio of 20 to 2 parts by weight and disperse uniformly. 6. The resulting aqueous dispersion is allowed to stand, centrifuged, or poured into methanol and taken out, followed by toluene/ethyl acetate, This can be achieved by dispersing it in an organic solvent such as 1,1,1-trichloroethane. If the amount of (B) used is less than 2 parts by weight, the binding effect cannot be improved, and if it is used in excess of 20 parts by weight, the adhesive particles are coated and the adhesiveness is lost.

In addition, in order to make a pressure-sensitive adhesive sheet that can be used repeatedly, it is necessary to coat the surface of a sheet-like substrate such as paper, cloth, nonwoven fabric, film, etc. with a bar coater, roll coater, spray, etc.
Approximately 2g/taki 2-3 in solid content by screen printing etc.
Just apply 0g/shoulder 2 times.

Furthermore, if necessary, adhesive granules may be disposed on a substrate coated with an anchor coating agent to obtain a pressure-sensitive adhesive sheet with less adhesive residue.

The anchor coating agents used to form the anchor layer include thermosetting resins such as polyurethane, melamine, and urea, and imino compounds, or carbon acetate or its anhydride, epoxy groups, etc. in the polymer molecule. Ami 7
Polymers containing functional groups such as hydroxyl groups and β-hydroxyl groups are applied in the form of aqueous solutions, aqueous dispersions, or solvent solutions and cured by heating, or vinyl acetate-acrylic acid ester copolymers, acrylic copolymers , natural rubber,
Using an adhesive polymer such as synthetic rubber, it is applied in the same manner as above and dried to form a film.

The anchor coating agent is used to improve the anchoring properties between the sheet-like substrate and the binder, or between the sheet-like substrate and the adhesive particles.

Therefore, when the sheet-like substrate is difficult to adhere to, such as a plastic sheet, it is particularly effectively used to improve the adhesiveness of the surface.

Solvent of the present invention! ! 1IW6 type adhesive granule dispensing liquid is applied to a sheet-like substrate, the adhesive granules are arranged on the surface of the substrate, and the contained binder fills and bonds between the adhesive granules, and the adhesive granules are The pressure-sensitive adhesive sheet bonded to the substrate has adhesive granules that swell in the solvent.
It has moderate rigidity and excellent, well-balanced adhesive performance, so when it is attached to an adherend and peeled off, there is no so-called paper tearing phenomenon in which the adherend is torn off, and the adhesive granules are strong. Since it is bonded to the base sheet,
There is no so-called adhesive residue phenomenon in which the adhesive granules migrate toward the adherend, and furthermore, it exhibits an excellent effect in that it can be repeatedly attached and peeled off many times. This is because (1) the copolymer that forms the sticky granules is internally porous using a specific monomer and a specific crosslinking agent, so it has little swelling property against solvents and has a well-balanced structure. Demonstrate adhesion performance.

(2) Since it contains a styrene-containing polymer having a smaller particle size than the adhesive granules as a binder, this binds the adhesive granules firmly onto the substrate, and also contains the styrene-containing polymer obtained by the second fL polymerization. The polymer has excellent interfacial chemical affinity with the adhesive granules, which are also obtained from an aqueous system, and has the effect of extremely strongly bonding the adhesive granules to the base sheet.

(3) In addition, the styrene-containing polymer made by this fL polymerization has a higher molecular weight than that made in a solvent system, so it has a higher cohesive force as a binder and strengthens the adhesive granules. It contributes to the effect of bonding to the base sheet.

(4) Even if this styrene-containing polymer has a high molecular weight, the styrene-based polymer itself has a high affinity for general solvents, so if it is dispersed in a solvent,
It exists in a uniformly distributed state, either dissolved or swollen, and easily forms a uniform film after drying, thus contributing to the effect of increasing bonding strength.

(5) Furthermore, in order to make a solvent-suspended adhesive granule dispersion, the mixed aqueous dispersion is treated with alcohol coagulation and dehydration as described above, but this styrene-containing polymer has excellent alcohol resistance. The fact that it can be coagulated and dehydrated without dissolving, and can be reduced in yield compared to acrylic polymers, etc., also contributes to the effect of increasing the bonding strength.

This is thought to be due to the effects of

Next, the present invention will be explained with reference to production examples, examples, and comparative examples.

Production Example 1 (Ingredients) (Parts by weight) Methyl methacrylate 152-ethylhexyl 7-acrylate 405 triallylisocyanurate
1.0 Maleic anhydride 4.0 Sodium polyacrylate (polymerized aooo -7000)
1.6 water
6007 Zoisoptilonitrile
2.0 Dodecylbenzenesulfonate 20
A polymerization reaction is carried out using the above components, and at least 8
An aqueous suspension of 0% sticky granules having a particle size of 80-100 microns was obtained.

Production example 2 (Ingredients) (Parts by weight) Styrene
12 Butyl acrylate 190 2-ethylhexyl acrylate 200 Tetraallyloxyethane 1.0 Maleic anhydride
5 hydroxyethyl cellulose
20 water
600 benzoyl peroxide 2.
0 Dotecylbenzenesulfonate A polymerization reaction is carried out using 20 or more components, and at least 80% of the particles have a particle size of 1.
An aqueous suspension of 5-50 micron sticky granules was obtained.

Road a side 3 (Ingredients) (Parts by weight) Methyl methacrylate 32 Isononyl acrylate 400 Triallyl cyanurate 3.7 Maleic anhydride 1.5 Hydroxyethyl cellulose 15 Water
SOO benzoyl peroxide 2.0 dodecylbenzenesulfonic acid 15 or more components are used to carry out a polymerization reaction,
An aqueous suspension of at least 80% sticky granules having a particle size of 45 to 70 microns was obtained.

Production Example 4 (Ingredients) (Heavy fi part) Methyl methacrylate 32 Isononyl 7 acrylate 400 Tetraallyloxyethane 2 Maleic anhydride 1.5 Polyvinyl alcohol 15 Water
eo.

Benzoyl peroxide 2.0 Dodecylbenzenesulfonic acid Sorg A polymerization reaction is carried out using an r&minute;
An aqueous suspension of 0 micron sticky granules was obtained.

Production Example 5 (Styrene-containing polymer emulsion) (Production
(parts by weight) Styrene
2002-ethylhexyl acrylate) 134 acrylic acid
10 polyoxyethylene nonylphenyl 5 ether sulfate (30%) polyoxyethylene/nylphenyl 5 ether (Eo
, 10-12 mol%) water
670 ammonium persulfate
Perform a polymerization reaction of 2 or more components with eyebrows -1 to make Pl + 8 to 9 111! Adjusted, average particle size 0.9
I got a micron emulsion.

Production Example 6 (Styrene-containing polymer emulsion) (Production
(parts by weight) Styrene
200 butyl acrylate
134 Acrylamide 4.
5 Methacrylic Fl! 12Se
e-Flucansulfonic acid 18 sodium (
01□～C1,) Water 8
70 potassium persulfate Perform a polymerization reaction using two or more components, adjust 9H to 8 to 9,
An emulsion with an average particle size of 0.036 microns was obtained.

Production Example 7 (Styrene-containing polymer emulsion) (1 &
(parts by weight) Styrene
23.2 Ethyl acrylate)
207.02-Hydroxyethyl acrylate 14 Acrylonitrile 1
4 Methacrylic acid 21 Trichlorobromomethane 2.8 Water
301.5 Sodium lauryl sulfate 3.3 Ammonicum persulfate
A polymerization reaction was carried out using 1.5 or more components to obtain an emulsion. Add 2 liters of water to this emulsion layer.
45 layers! I1. 114 parts of 5.6% ammonia water were added and aged for 1 hour to obtain an emulsion with an average particle size of 0.069 microns.

Production Example 8 (High Styrene Content Polymer Emul?, 13 N) (
711 minutes) (parts by weight) Styrene
268 Butyl 7 Acrylate
66 Acrylic 7 Mid 4
・5 Methacrylic l! l112 water
670 Potassium persulfate Use two or more components to complete the polymerization reaction, adjust p++ to 8 to 9, average particle size 0.04 microns, styrene-containing fi
He achieved a two-mark polish of 76.4%.

Sll example 9 acrylic polymer emulsion 3) (formation)
min) (!!j1 part) Methyl methacrylate 2002-ethylhexyl acrylate 134 acrylic @
10 Polyoxyethylene/Nylphenyl 5 Ether Sulfate (30%) Polyoxyethylene/Nylphenyl 5 Ether (Eo
, 10-12 mol%) water
6F Ammonium Persulfate Perform a polymerization reaction using two or more components, adjust the pH to 8 to 9, and obtain an average particle size of 0.
．． An 83 micron emulsion was obtained.

Production Example 10 (Acrylic Polymer Emulsion 5) (Production
(parts by weight) Methyl methacrylate
200 butyl acrylate
134 Acrylamide 4.5
Methacrylic! 12 Water
670 Potassium persulfate Perform a polymerization reaction using two or more components, and the pfl is 1 in 8 to 9!
4 to obtain an emulsion with an average particle size of 0.04 microns.

Examples 1-8, Comparative Examples 1-6! 13i! Adhesive granule dispersion obtained in 13m4 and Production Example 5
The banhgu obtained in Steps 7 to 7 and the binders for comparison obtained in Production Examples 8 to 10 were mixed in the proportions shown in Table 1, poured into methanol to coagulate, washed, and then the lump resin was taken out and mixed with a solvent. The mixture was added to toluene and redispersed by stirring to prepare a solvent-suspended adhesive granule dispersion with a concentration of 25%.

Then, it was coated on high-quality paper (55K) using a table-top coater to give a dry weight of 7 to 917 m'', and dried with hot air at 40°C for 1 minute to obtain a pressure-sensitive Ij: coated sheet.

Example 9 As an anchor coating agent, approximately 1.5 ml of Cohonyl 4081 (a 50% methanol solution of acrylic/vinyl acetate copolymer m plate manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd.) was applied to high-quality paper (55K).
Prepare a base material that has been coated with g/x2 and dried, and apply the 25% concentration solvent-suspended adhesive granule dispersion used in Example 1 to this base material using a tabletop coater and dry it. Weight 7-9 g/
x'' and dried with hot air at 40°C for 1 minute to obtain a pressure-sensitive adhesive sheet.

Comparative Test The pressure-sensitive adhesive sheets obtained in Examples 1 to 9 and Comparative Examples 1 to 6 were tested for adhesive retention, degree of swelling, number of repeated adhesion, paper removal, adhesive strength, and tack.

The test results are shown in Table 1.

(Test method) Adhesive residue test A pressure-sensitive adhesive sheet test piece (20 mm in adhesive side, length 10011) lined with commercially available plastic film tape was attached to a commercially available Miracoat paper lined with a stainless steel plate, and JIS Z 0237 was applied. After 2 hours of pressure bonding with a 2 kg rubber roller specified by , it was peeled off at a peeling speed of 30i + / win, and the transferability of the adhesive particles to the mirror coated paper surface was measured by weight, Cn = 3) Transfer rate (weight %) It was expressed as

Swelling degree (change rate) of particles Approximately 30 g/I of the above solvent-based suspension was applied to a polyester film with a thickness of 38 microns, and immediately after application and at room temperature 30
The rate of change in particle diameter after minutes was determined and was defined as the moisture content of the particles.

Particle size after 30 minutes However, the particle size was measured using a microscopic photograph.

Repeated contact/peeling times Adhesion/peeling was repeated on the printed newspaper surface, and the number of times until adhesion stopped was determined.

We also checked for paper tearing, which is a serious problem in printing.

Adhesive physical properties According to JIS Z 0237, adhesive strength (g/25zi
+) and tack (ball No.) were measured.

From the results in Table 1, the solvent-suspended adhesive granules obtained by the present invention have a swelling degree (rate of change) of 1.8 to 2.3, which is extremely normal. In a solvent solution, sticky granules usually swell to about twice the diameter and about 8 times the volume, and when the spherical solvent evaporates when applied to the substrate, they shrink. The diameter becomes approximately 1/2. In other words, the rate of change is 2.

However, when it is applied to a substrate, if it loses its shape or flows, its diameter becomes larger than the original diameter of 172 mm when viewed from above, and sometimes becomes larger than the original diameter. When this happens, it will no longer be point adhesion,
This may cause paper tearing. In addition, in the case of 0-piece molding, which reduces the number of repeated peeling, the adhesive granules are made using a special internal crosslinking agent, so the degree of swelling (rate of change) is 1.7 to 2.2 even in the comparative example. Very normal.

Therefore, no paper-picking phenomenon was observed in either case.

The pressure-sensitive adhesive sheet obtained by the present invention had very little adhesive residue and exhibited a large number of repeated peelings of 40 times or more. Moreover, the adhesive force also showed an appropriate value of 87-110g/25ii+, and the tack (ball No.) also showed an appropriate value of 5-6.

On the other hand, in Comparative Example 1, an emulsion with a high styrene content was added as a binder, and in Comparative Example 4, a large amount of styrene-containing emulsion was added.
Adhesive residue, swelling degree, and paper removal were good, but adhesive strength was low.
However, both the tack and the number of times of a-turn peeling were low.

Comparative Examples 2 and 3 used acrylic emulnol as a binder, so when it was poured into methanol to coagulate and wash, it was dissolved in methanol and washed away, and as in comparative example 5, styrene-containing emulnol was If you use a small amount,
Similar to the case where no binder is used as in Comparative Example 6,
It showed extremely large adhesive residue.

(September 6, 1985, Commissioner of the Patent Office) Pressure Sensitive Adhesive Sheet Agent 4 Agent: 540 Address: 60 Kyo 113-chome, Higashi-ku, Osaka, North Building Name: (6522) Patent attorney Sota Asahina Phone (06) 943-8922 (Main) Haka 1 person subject to 5 corrections (1) Mei I! III “Detailed Description of the Invention” Column 6
Contents of amendment (1) “Myriad maleic acid” on page 9 of the specification, lines 9-10
Correct it to "maleic anhydride".

(2) Correct “(a, mountain), (C)” on the last line of page 9 to “(al, mountain), (C), (d)”.

that's all

Claims (1)

[Scope of Claims] 1 (A) (a) Methyl acrylate and/or methacrylate of styrene and/or alcohol having 1 to 5 carbon atoms 2 to 10% by weight (b) Acrylate of alcohol having 2 to 12 carbon atoms and /or methacrylate of alcohol having 6 to 12 carbon atoms 98 to 90% by weight (c) maleic anhydride 0.1 to 2.0% by weight (d) selected from tetraallyloxyethane, triallyl cyanurate, triallyl isocyanurate 100 parts by weight of internally crosslinked adhesive granules with a particle size of 5 to 200 microns obtained by copolymerizing 0.05 to 1.0% by weight of one or more types (B) Styrene content 5 to 70% by weight A solvent suspension type consisting of a styrene-containing polymer having a particle size of 0.02 to 3 microns, (A) a binder (in terms of solid content) of adhesive particles, and 2 to 20 parts by weight (C) an organic solvent. Adhesive granule dispersion. (a) Methyl acrylate and/or styrene and/or methacrylate of an alcohol having 1 to 5 carbon atoms disposed on the surface of the 2-sheet substrate (b) Acrylate of an alcohol having 2 to 12 carbon atoms and/or 2 to 10% by weight or methacrylate of alcohol having 6 to 12 carbon atoms 98 to 90% by weight (c) maleic anhydride 0.1 to 2.0% by weight (d) selected from tetraallyloxyethane, triallyl cyanurate, triallyl isocyanurate Internally crosslinked bound particles having a particle diameter of 5 to 200 microns obtained by copolymerizing 0.05 to 1.0 wt. and a styrene-containing polymer with a styrene content of 5 to 70% by weight, which binds the adhesive granules to the base sheet, and has a particle size of 0.02 to 3 microns, and has a particle size of 2 to 20% by weight with respect to the adhesive granules. A pressure sensitive adhesive sheet consisting of a binder in an amount of % by weight. (a) methyl acrylate and/or methacrylate of alcohol having 1 to 5 carbon atoms and/or styrene 2 to 10% by weight (b) Acrylate of alcohol having 2 to 12 carbon atoms and/or methacrylate of alcohol having 6 to 12 carbon atoms 98 to 90% by weight (c) Maleic anhydride 0.1 to 2.0% by weight (d) Tetraallyloxyethane, tri Internally crosslinked adhesive granules with a particle diameter of 5 to 200 microns obtained by copolymerizing 0.05 to 1.0% by weight of one or more selected from allyl cyanurate and triallyl isocyanurate, and the adhesive A styrene-containing polymer having a styrene content of 5 to 70% by weight, which fills and binds the particles and binds the adhesive particles to the base sheet, and has a particle size of 0.02 to 3 microns, and which binds the adhesive particles to the base sheet. A pressure-sensitive adhesive sheet comprising adhesive granules and a binder in an amount of 2 to 20% by weight.