JPS6181476A - Thermosetting adhesive sheet - Google Patents

Abstract

PURPOSE:The title sheet that is prepared by coating a base material with a cold-tacky, thermosetting resin composition which is prepared by adding a specific amount of short-cut fibers to a resin component containing a thermosetting resin and a thermoplastic resin, thus showing pressure-sensitive adhesion, when a small body such as a hook is adhered to a substrate. CONSTITUTION:A thermosetting resin composition is prepared by adding (A) 3-30pts.wt. of short-cut fibers, preferably with an aspect ratio of 50-1,000, less than 10 micron thickness, e.g., rock wool or polyester staple fibers to 100pts. wt. of a resin composition consisting of (A) a thermosetting resin, preferably an epoxy resin of 150-250 epoxy equivalent and (B) a thermoplastic resin, which is compatible with resin A such as a thermoplastic polyester resin, preferably in an amount of 2.5-30wt%. The bse materialis coated or impregnated with the resultant cold-tacky thermosetting resin composition to give the objective sheet.

Description

Detailed Description of the Invention (a) Industrial Field of Application The present invention exhibits pressure-sensitive adhesive properties when attaching small articles such as name plates, 77 snares, 7 tsuku, etc. to adherends. The present invention relates to a thermosetting adhesive sheet that can securely hold an article without shifting after it has been adhered to an adherend, exhibits strong adhesive force when heated, and has excellent heat resistance.

More specifically, it is a thermosetting adhesive sheet made by coating or impregnating a base material with a thermosetting resin composition that is adhesive at room temperature and formed by mixing short fibers into a resin component. A thermosetting 8M sheet that can be easily adhered to the adherend by pasting it on the other side of the article, and can be cured and firmly adhered to the adherend without causing any positional shift or resin extrusion during heat curing. Regarding.

(b) Prior art Conventionally, adhesive sheets for attaching small articles to adherends have been used.
Pressure-sensitive adhesives based on various thermoplastic resins, such as adhesive tape, are widely used, but these adhesives have weak adhesive strength and are thermoplastic (based on fat). Therefore, it is difficult to use it in areas where heat resistance, strength at high temperatures, or strong adhesion is required.6Especially, at high temperatures of 60°C or higher, the adhesiveness of the adhesive is extremely reduced. As a result, the adhesive strength is significantly reduced, causing problems such as peeling and falling off.

Therefore, as an adhesive to be used in such areas, adhesive thermosetting adhesive (1) has been attempted to be used, but
With the conventional thermosetting L (resin composition), after adhering the small article to the T adherend, it is necessary to open the resin composition until it heats and hardens, and then requires an adhesive jig to temporarily fix the small article. If this jig or some kind of temporary fixing means is not used, there is a problem that small articles may become unusable due to poor adhesion such as misalignment or falling off before the resin composition is cured. Small articles can be bonded by using a large amount of thermosetting resin composition, but during bonding, this resin composition may protrude and stain the area around the small article, or in some cases, the resin composition may There were problems such as having to remove the protruding parts after curing.Fine powder synthetic silica is generally used as an agent to prevent the resin composition from shifting or extruding the resin, but thermosetting UL fat 10
Unless 15 parts by weight or more of finely powdered synthetic silica is added to 1 part of Offfi, it will not have enough adhesive strength to hold the small articles from the time they are bonded until they are heated and cured.On the other hand, When such a large amount of finely powdered synthetic silica with a low bulk density is added, the initial adhesiveness of the resin composition at room temperature decreases, making initial adhesion to an adherend difficult. Furthermore, when kneading into the resin, excessive kneading tends to reduce the retention properties, making it impossible to obtain retention properties with good reproducibility. Furthermore, there were also drawbacks such as a change in retention strength over time and a lack of stability during storage.

(C) Object of the Invention The present invention exhibits pressure-sensitive adhesive properties in the 71st step of adhering a small article to an adherend, and after adhering the small article to the adherend until it is heated and cured, the small article We aim to solve the above problems all at once by providing vE thermosetting adhesive sheets that have the necessary adhesive strength to hold adhesives on adherends and also exhibit strong adhesive strength after heat curing. ru.

(d) Structure of the invention, that is, the present invention provides 3 parts by weight of short fibers per 100 parts by weight of the resin component.
-30 parts by weight are mixed to form a thermosetting resin composition that is sticky at room temperature, and the thermosetting resin composition is applied or impregnated onto a substrate.

In the present invention? The H fatty acid component is thermosetting (11 fatty acids (A
) and thermoplastic resin CB+. The above (A) may be in liquid or putty form, for example,
Thermosetting resins such as thermosetting epoxy resins, thermosetting polyester resins (so-called thermosetting acrylic resins, etc.) include thermosetting resins, especially thermosetting resins with an epoxy equivalent of 150 to 250 that are sticky at room temperature. It is preferable to add a curing agent to the epoxy IJ1 resin, and the above (Bl) is one that is compatible with the above (A), such as thermoplastic polyester resin, thermoplastic diboxyl resin. , butyral resin, copolyamide, rubber-based resin, and other thermoplastic resins, but rubber-like materials can also be used in the present invention. The purpose of adding the thermoplastic If resin (B) is to improve the adhesion and fluidity of (A) before curing, and to improve and impart initial tackiness at room temperature.

The addition ratio of the above (B) is 2.5 to 35% by weight, preferably 5 to 25% by weight based on the total weight of the above (A) and (B).
If it is too small (less than 2.5% by weight), it will not be possible to improve the adhesion or fluidity, while if it exceeds 35% by weight, the initial tackiness will decrease and the fluidity will also decrease. This is not desirable as it will make things worse.

In addition, when the thermosetting resin (A) is an epoxy resin,
It is necessary to add a hardening agent.

Examples of the curing agent include amines such as noethylenetriamine, metaphenylenenoamine, and noaminophenylmethane, heptatalic anhydride, maleic anhydride,
Carbo/acid anhydrides such as anhydrous chlorsuccinic acid P2, BF,
Examples include compounds such as i-complex compounds and nocyanoamides. And the f history amount of this hardening agent is Evokin yarn! (The ratio of the epochine equivalent of citrus fruit to the functional group equivalent of 1j before curing is (),
If it is less than 0.8, it will not be possible to form a transparent reticular adhesion as an adhesive.
As a result, problems arise with adhesive strength after curing.
On the other hand, if it exceeds 1.5 degrees, it is not preferable because the properties of the adhesive after curing deteriorate.

Further, when (A) is a thermosetting polyester resin, for example, a thermosetting polyester resin consisting of an unsaturated dibasic acid and Glyfur, a curing catalyst is required. Examples of this catalyst include L-butyl hydroperoxide, cume/hydroperoxide, benzoyl peroxide, and cyclohexanone peroxide. The amount of this catalyst used is 100% of the above thermosetting polyester resin.
It is preferably in the range of 0.1 to 5' parts by weight.

Furthermore, in the case where (A) is a thermosetting acrylic resin (for example, a thermosetting acrylic resin modified by introducing an Evoquine group), the curing agent may include the above-mentioned 7min neck, carboxylic acid anhydride,
Examples include compounds such as BF3 complex compounds and nocyanamide. The amount of curing agent used is preferably within the same range as for the Evoquin resin.

A major feature of the present invention is that short fibers are mixed into the above fat component to form a thermosetting resin composition that is sticky at room temperature.

In other words, a thermosetting resin composition that is adhesive at room temperature and is formed by mixing short fibers into a resin component can be used to hold small articles after adhering them to an adherend and before curing them by heating. It can be held securely without causing problems such as falling off or slipping off. Examples of such short fibers include rock wool, woven fibers, and asbestos fibers. There are organic short fibers such as high quality short fibers, polyester, vinylon, etc., and metal short fibers.

The above-mentioned short fibers have good dispersibility, especially those whose aspect ratio, that is, the ratio of fiber length to diameter, is in the range of 50 to 1000, and whose fiber diameter is 10μ or less, and which are uniformly mixed and thermosetting. The adhesive properties of the resin composition are stable, and as a result,
The holding strength of the small article is stable and the small article can be held reliably.

In addition, the amount of the above [a fiber added is 100% of the above resin component]
3 to 30 parts by weight, preferably 5 to 20 parts by weight
If the amount is less than 3 parts by weight, the holding strength will be low, and if it exceeds 30 parts by weight, it will be difficult to mix wires into the resin. The initial tackiness of the composition at room temperature decreases, which tends to cause problems in the initial tackiness to the adherend (1+) In the present invention, the above resin component is free of bulking agents such as talc and calcium carbonate, In addition, various fillers are added, such as materials that give cyclotronic properties such as alumina and silica powder, and materials that affect properties such as abrasion resistance, coefficient of thermal expansion, and thermal conductivity, such as aluminum, copper, and iron. It is okay to do so.

The usage amount of this Hikari J ingredient is preferably in the range of 50 to 200 parts by weight per 100 parts of the 11 ingredients.Also, various hardening accelerators may be added to the above fat ingredients. The amount of the curing accelerator used is preferably in the range of 0.1 to 3 parts by weight per 100 parts by weight of the resin component.

These thermosetting resin compositions having room-temperature tackiness are coated or impregnated onto a substrate in an uncured or semi-cured state while heating the composition to usually 50 to 100°C. Use as an adhesive sheet.

Examples of the above-mentioned base material include inorganic fiber cloths such as plas, organic fiber cloths such as cotton, polyester, acrylic, and vinylon, and nonwoven fabrics. In the present invention, when the thermosetting FBI resin composition is applied onto a separator and the resin composition is transferred to a small article during use, the separator becomes a base material. It is.

(e) Effects of the invention The thermosetting adhesive sheet of the present invention having room temperature adhesiveness thus obtained exhibits pressure-sensitive adhesion when a small article is pasted on an adherend, and adhesive properties such as Even without using the adhesive, the small article can be firmly held without causing problems such as positional displacement or resin extrusion until the 01 resin becomes stone.

In addition, by heating, it exhibits strong adhesive strength, and it also has excellent heat resistance and adhesive strength at high temperatures. It is possible to form layers with good workability even in areas where high adhesive strength is required (1), and it can also be used in a wide range of general applications.

(nExamples 1 to 19 and Comparative Examples 1 to 9 A predetermined amount of thermosetting resin and a predetermined amount of thermoplastic resin shown in 1a were placed in a mixing pot at 120 to 190°C, ul
L<11130-160'Ct' Melt mix for 1 hour.

After confirming that these components are completely compatible, 11
While lowering the temperature to 0-130℃ and maintaining this temperature,
Add a predetermined amount of short fibers shown in Table m1 and heat and mix for 30 to 40 minutes. In this case, a predetermined amount of filler may be added 6 Then reduce the temperature to 90-100'C and
After heating and stirring a predetermined amount of the curing agent shown in the table for 30 minutes in a pot, a predetermined amount of a curing accelerator is added and the mixture is heated and mixed for 5 to 10 minutes. After mixing, immediately remove from the mixing pot and cool to room temperature. The obtained thermosetting resin composition has tackiness at room temperature.

Moreover, Comparative Examples 1 to 9 were also prepared in the same manner as in the above examples.

In this case, when creating the thermosetting resin composition of Comparative Example 8, fine powder synthetic silica is easily scattered during cross-wire (,
Mixability with NT fat was poor.

In Table PJ1, parts mean parts by weight.

(Left below) Various thermosetting 43411tr compositions of Examples 1 to 1 and Comparative Examples 1 to 9 shown in Table 1 were used as a separator (base material).
200 g of the resin composition was placed on the upper surface of the separator by introducing it onto a heated roll (temperature: 80 to 90°C).
A thermosetting adhesive sheet that is sticky at room temperature is prepared by applying the adhesive at a ratio of 100 mm.

The results of investigating the performance of the thermosetting adhesive sheet thus prepared are shown in Table 2.

(Left below) and l:1) Test 9 in 25IIIIII. Attach sheet 1 to a stainless steel plate, and apply one-way pressure to sheet 2 with a roll.

Crimp and 3 (test after 1 minute) Bend the end of 1 to 13 ( ) degrees and pull it to iM degrees of 511 + n + n + l)! Peel it off and measure the peeling force at this time.

? ) As shown in the figure, l fl run (ft 3
) X 5 fl + nm (width) adhesion/) (F of the same shape as 11) + 1' plate (weight 2, (1.

Each of ゛(,5n) // +7'+11j! Paste it on
], use this as test piece (2), 7 fl nunL
(middle) r Boshin H, 2, 'J I) 5 has a large amount, hardening? &'s F' RP @
Evaluate the position status of.

3) Two rolled steel plates with a thickness of l and G +++m were used as the body, and a test piece was placed between the two steel plates by fFVc.
Heat for 30 minutes at 1'l'C.
Determine the shear strength of all 414 C shear strength using JIS K-685 (), 4) Use two steel plates with a thickness of 0 and 8 m + @ thickness. death,
A test piece was inserted between both steel plates, and the sheet was heated at 150°C for 3 C1 minutes.
Measure the 18() degree) q separation strength over 54 minutes.

5) Measure the tensile shear strength in the same manner as in 3) above, except that the measurement temperature is 70°C. .

6) Using an adhesive sheet stored for 30 days in an atmosphere at a temperature of 20'C1 relative zd degree of 65%, the retention property was evaluated in the same manner as in 2) above.

As is clear from the above test results, the thermosetting adhesive sheet of the present invention has high pressure-sensitive adhesive properties, and also has a high resistance to opening and misalignment of small objects until it is heated and cured after adhering small objects. It can be seen that the adhesive does not cause peeling or falling off, and has excellent adhesive properties after heat curing, hot strength, and storage stability.

[Brief explanation of the drawing]

The figure shows a method for evaluating retention. (11... Thermosetting adhesive sheet, (2)... Test piece, (3)... Degreased steel plate, (1)... Length of positional shift. Patent applicant: Nichizuka Electric Industry Co., Ltd. (1)...Thermosetting adhesive sheet, (2)...Test piece, (3)...
... Degreased steel plate, (1) ... Length of positional deviation,
r-Continued Amended Horoscope 1, Incident Display Special N Book 59-203670 No. 2
, Title of the invention Thermosetting adhesive sheet (, III
Relationship with the case of a person who abuses I-Sho Patent applicant address Ibaraki City, Osaka Prefecture! ! ! Product 1-1-2
Name: Nippon W, Denki Kogyo Co., Ltd. 4; Agent address: 1-12-19-6 Nishihonmachi, Nishi-ku, Osaka; Subject of amendment: “Brief explanation of the drawings” in the specification.
Column and drawing 7, content of amendment (1), “The drawing...
" is corrected to the following sentence. (1)...Thermosetting 11 sheets, (3)...Ha tip fat-SI! After l, (1)...
・(2)...Shiwaki piece, position@su°°dashinomoteno

Claims (4)

[Claims] (1) Thermosetting resin composition having adhesiveness at room temperature by mixing 3 to 30 parts by weight of short fibers with 100 parts by weight of a resin component containing a thermosetting resin (A) and a thermoplastic resin (B). 1. A thermosetting adhesive sheet comprising a base material coated with or impregnated with the thermosetting resin composition. (2) The thermosetting adhesive sheet according to claim 1, wherein the amount of (B) is 2.5 to 35% by weight based on the total weight of (A) and (B). . (3) The aspect ratio (length/diameter) of the above-mentioned short fibers is
The thermosetting adhesive sheet according to claim 1 or 2, which has a thickness of 50 to 1000 and a thickness of 10 μm or less. (4) The thermosetting resin has an epoxy equivalent of 150 to 250
The thermosetting adhesive sheet according to any one of claims 1 to 3, which is an epoxy resin.