JPS62158772A - Pressure-sensitive adhesive - Google Patents

Abstract

PURPOSE:To obtain a pressure-sensitive adhesive which has excellent adhesiveness, heat resistance, blocking resistance, abrasion resistance, etc. and is suitable for sticking of, e.g., a letter form sealed by folding in three, by incorporating a silica gel into an SBR latex having a content of styrene in a specified range. CONSTITUTION:5-40pts.wt. silical gel is incorporated into 100pts.wt. SBR latex having a content of styrene in SBR of 50-75%, thus giving an objective pressure-sensitive adhesive. As the silica gel, a fine powder having an average particle diameter of 1-10mum is suitably used. If necessary a dispersing agent, a wetting agent, a thickening agent, an anti-foaming agent, etc., can also be incorporated into the adhesive in addition to the silica gel. The pressure-sensitive adhesive 2 thus obtained is used, e.g., by applying it in advance to the sticking part of a letter form 4 sealed by folding in three.

Description

Detailed Description of the Invention [Field of Industrial Application] This invention is a method of applying an adhesive in advance to a predetermined portion of a printing form such as paper or a form on which information is to be printed, and then applying an adhesive after printing. This is a pressure-sensitive adhesive that is used to bind printed forms together by applying pressure, which is the adhesive condition. It is used as an adhesive for binding books, booklets, etc.

[Problem with the prior art 1 Conventionally, forms for various types of printing such as paper and forms 1a
Natural rubber, synthetic rubber,
There are those whose main components are synthetic resins, etc., and various types have been selected and used depending on the purpose.

In recent years, many printers called non-impact printers have begun to be used, and some of these non-impact printers that use an electronic recording method use heat and pressure to fix the toner. Pressure-sensitive adhesives whose main ingredients are thermoplastic synthetic rubber or synthetic resin,
The adhesive softens inside the printer, causing accidents and inconveniences such as the softened adhesive adhering to the printer.

In addition, pressure-sensitive adhesives whose main component is natural rubber have low adhesive surface strength, which causes problems such as accidents such as 1A adhesive being deposited inside the printer and the printer being removed. It was without one.

Furthermore, when the above-mentioned conventional pressure-sensitive adhesives were used by applying them to printing materials (for printing), they were not satisfactory in terms of one-way adhesion, heat resistance, blocking resistance, and storage stability.

[Means for Solving the Problems 1] As a result of extensive research, the present inventor has decided to add silica gel at a specific ratio to SBR latex having a styrene ratio within a specific range, thereby achieving the desired purpose. The inventors have discovered that a pressure-sensitive adhesive can be obtained that can achieve the above-mentioned results, and have completed the present invention.

In the present invention, the styrene ratio in SBR is 50 to 7.
5%, preferably 60-70% SBR latex 10
0 parts by weight contains an average particle size of 20μ or less, preferably 1 to 10μ
, more preferably by adding 5 to 40 parts by weight of silica gel of 2 to 6 μm, preferably 15 to 30 mm parts,
By dramatically improving adhesive strength, heat resistance, abrasion resistance, blocking resistance, and storage stability, we were able to obtain a pressure-sensitive adhesive with superior performance compared to conventional pressure-sensitive adhesives.

The SBR latex and silica gel in the present invention are
As described in the examples, b consisting of various styrene ratios and particle sizes can be applied, and styrene ratios from 60 to
70% SBR latex 100 heavy parts with average particle size of 1~
Products to which 15 to 30 m of silica gel of 10 μm are added have particularly excellent adhesive properties and are suitable for use in mailing envelopes, postcards, and various cards, and are described in other examples. Pressure sensitive adhesives can also be used advantageously for bonding and binding applications of paper and forms.

Even if SBR latex is applied to paper as a pressure-sensitive adhesive and dried, the adhesives are brought into contact with each other and pressure is applied, the adhesiveness is weak. Similarly, the pressure-sensitive adhesive of the present invention has a weak adhesion property by itself, but the pressure-sensitive adhesive of the present invention combines silica gel with SBR.
It exhibits effective performance as a pressure-sensitive adhesive by placing 5 to 40 parts of latex in 5 to 40 parts per 100 parts of latex.The reason for this is not clear, but SBR is adsorbed to silica gel. The surface area is increased, the silica gel acts as a kind of reinforcing agent and the strength of the adhesive is increased, and the pressure sensitive adhesive 2 applied to the printing form 1 at a thickness of about 5 μm as shown in FIG. This seems to be due to the fact that the coated surface becomes uneven due to the silica gel 3.

The pressure-sensitive adhesive of this invention is made by adding silica gel to SBR latex, but if necessary, a dispersant,
A wetting agent, thickener, antifoaming agent, etc. can also be added.

[Example 1 Next, the present invention will be described in more detail with reference to Examples.

Since it is clear that other embodiments may be constructed in the form of a wide box without departing from the spirit and scope of the invention, the present invention is not limited to these specific features except as limited in the scope of the claims. It is not limited to the actual ms.

Note that throughout this specification, all parts refer to the fffffi part. Further, the various performances of the Examples and Comparative Examples were measured by applying the pressure-sensitive adhesive onto paper to a thickness of about 5 μm using the following method.

For adhesive double prints) A sealing machine for pressure bonding was used. The pressing force is approximately 100 kg/ci.

Blocking resistance: Approximately 500 IJ/a in a constant temperature bath at 30° to 10°C
After leaving it for 1 hour while applying a load of i, a release test was performed using a Tensilon universal tensile tester.

Abrasion resistance: The strength of the adhesive surface was examined by abrading the adhesive surface with a 9/ci cart from 200 to 500/J.

Heat resistance: Apply a load m of 1 to 3 K'j/cm, and
The state of the adhesive surface was examined by pressing it against a hot roll at 00°C.

Example 1 SBR latex [Niball LX 204J (product name; manufactured by Rohon Uon Co., Ltd., styrene ratio 55%, solid content 4
1%) 100 double finger silica gel “5IPERN8T
12 fold fa parts of 22SJ (trade name, manufactured by Niki Aerosil Co., Ltd., particle size: 5 μm) were added and sufficiently stirred to prepare a pressure-sensitive adhesive.

Same <SBR latex [two-ball LX 204J1
Silica gel "SIP [Rt4^T 22S
J 20 parts by weight was added to pressure sensitive adhesive B to F! Made by A.

Same < 8 [3r < Latex [Two poles LX 2
04J100 Silica gel r 5IPERN^T
Pressure sensitive adhesive C was prepared by adding 22SJ 26 overlapping parts.

Example 2 SBR latex r [IL 636J (trade name; manufactured by Asahi Kasei Corporation, styrene ratio 60%, solid content 48%) 100 silica gel [Syroid 244J (trade name; manufactured by Fuji Davison Corporation, particle size 3μ) was added to 100 parts of the weight. A pressure-sensitive adhesive was prepared by adding 1.5 parts by weight and stirring thoroughly.

A pressure sensitive adhesive E was prepared by adding 20 parts by weight of silica gel "Syroid 244" to 100 parts of the same SBR latex "DL 636J".

Same < S 13 R latex Slo silicon 6364 100
Pressure-sensitive adhesive F was prepared by adding 35 parts of silica gel "Syroid 244" to the same part.

Example 3 S [3R latex "Ks 1101 J (prototype product 2, manufactured by Nippon Synthetic Rubber Co., Ltd., styrene ratio 65%, solid content 47
．． 0%) 1 part of 100mff contains 13 parts of silica gel "N-300" (trade name: Nippon Silikani Gyo Co., Ltd., particle size 3μ).
．． 71 fi parts were added to prepare a sufficient Wtl\L pressure sensitive adhesive G.

File S [3R latex l”KS 1101 j
1001D Part of silica gel [Nip Shield 30
A pressure sensitive adhesive H was prepared by adding 27.4 parts of 0AJ.

Example 4 SBR latex INAUGAIEX 5N-540J
(Product name: Manufactured by Sumitomo Nogatack, styrene ratio 7
0%, solid content 51%> silica gel [Thyroid 404. 151 parts of + (trade name: 't

Same <SBR Latex rNAtlGATEX 3N-
540,1100 weight 11ik: shi'J h ke)shir
Pressure sensitive adhesive J was prepared by adding sIP[llNAr 22SJ and 26ifi.

Add tackifier to 100 parts by weight of natural rubber latex.
Hytanol 1501J (product name; manufactured by Hitachi Chemical Co., Ltd.)
Add 31 parts of casein and further add 10 parts of casein ff1-F.
! 1 was added to prepare pressure sensitive adhesive K.

Comparative example 2 SBR Larx rNAllGATEX J9049
” (Product name: Manufactured by Sumitomo Naugatuck, styrene ratio 46
%, solid content: 49%) 1 part of 100 mff was added with 15 weight R% of silica gel "Syroid 244" to prepare a pressure-sensitive adhesive.

Anonymous ■-1 SBR latex "JsR0602J (Product name: Manufactured by Japan Synthetic Rubber Co., Ltd., styrene ratio 85%, solid content 52%)
Silica gel "Thyroid 244" in the 10OflXffi section
'' was added in an amount of 20 parts to prepare a pressure-sensitive adhesive M.

Comparative example 4 SBR latex [S 1101 J 100
Apply 3 pieces of silica gel [Nip Seal N-300^] to the heavy foot area.
．． A pressure sensitive adhesive N was prepared by adding 5 parts by weight.

43.5 parts of silica gel "N-3008" was added to 100 parts by weight of SBR latex and pressure sensitive i! @ Agent O vA! I did J.

Pressure-sensitive adhesives A-J of the present invention prepared in Examples 1 to 4 above
Table 1 shows the test results for adhesion, blocking resistance, heat resistance, and abrasion resistance of vA pressure sensitive adhesives prepared in Comparative Examples 1 to 5.

Table 1 [Effects of the Invention] As is clear from the test results, the pressure-sensitive adhesive of the present invention has excellent performance in all items of adhesiveness, blocking resistance, heat resistance, and abrasion resistance. It is something that exists.

Therefore, the pressure-sensitive adhesive of the present invention can be applied to a form 4 for tri-fold seal 79 shown in FIG. 2, which is a type of printing form.
It is particularly effective to apply the pressure-sensitive adhesive 2 of the present invention to a thickness of about 3 to 6 μm in advance on the bonded portion of the two-sheet sealing foam 5 shown in FIG. In addition to the printing forms shown in Figures 2 and 3, it can be pre-painted on printing forms such as tri-fold envelope forms, postcard forms, various notice forms, binding forms, and window-perforated tri-fold envelope forms. It is effective for use in 11 cases.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing the state in which the pressure-sensitive adhesive of the present invention is applied onto a printing form. Figure 2 is an explanatory diagram showing the pressure-sensitive adhesive of the present invention applied to a tri-fold envelope form, which is a type of printing form. An explanatory diagram showing the state in which the pressure-sensitive adhesive of the present invention is applied to the pudding! - It is an explanatory diagram showing a state in which two sheets of letter form, which is a type of letter form, are coated. 1... Printing foam 2... Pressure sensitive adhesive 3... Silica gel 4...
・Form for three-fold envelopes 5...Form for double-fold envelopes 6...Perforations for folding 7...Perforations for cutting 8...Sewing machine for opening [1 14th edition Applicant: Totsuban Moore Co., Ltd. 1 ,1i Figure 1 Figure 2

Claims (1)

[Claims] A pressure-sensitive adhesive characterized in that 5 to 40 parts by weight of silica gel is added to 100 parts by weight of SBR latex having a styrene ratio of 50 to 75%.