JPS62149774A - Adhesive for glass - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which has excellent adhesion to glass, does not cause peeling due to residual stress during curing and allows firmly bonded cured article to be easily cut and separated from glass, containing a specified radical-polymerizable compd. and a photopolymerization initiator. CONSTITUTION:20-99.9wt% at least one compd. (A) selected from among radical-polymerizable compds. of the formula (wherein R1 and R2 are each H or methyl; R3 is an alkyl group; n is 1 or above- is blended with 0.1-10wt% photopolymerization initiator (B) (e.g., 2-hydroxy-2-methyl-1-phenylpropan-1-one) and optionally, a silane coupling agent, a dye, a pigment, etc. (C).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel glass adhesive that can be used in the production of laminated glass.

[Conventional technology]

Laminated glass, which is made by laminating multiple glass plates and bonding them together, is superior in terms of safety and is used as safety glass for automobiles and implosion prevention glass for large televisions.

The intermediate layer, such as a cured adhesive layer, that is interposed between the glasses of the laminated glass used for these applications has a toughness that will not break even if the glass breaks, as well as excellent adhesion to the glass. It is required to have a transparent it.

One method for manufacturing laminated glass is to insert a resin film as an intermediate layer between glass plates, pre-press the resin film, and then perform final press-bonding while heating in an autoclave. However, this method has complicated steps and requires autoclave treatment, making continuous production difficult and resulting in increased manufacturing costs.

Another method for manufacturing laminated glass is to stack glass plates on top of each other via a processor, seal the edges, inject a liquid adhesive, and cure with heat or light. This method has superior productivity compared to the method using an autoclave, but when using the conventional liquid adhesive described in JP-A No. 58-17'2851, shrinkage occurs during curing. Due to the accompanying internal stress and the internal stress due to the difference in coefficient of thermal expansion between the glass and the intermediate layer during heating or cooling, the intermediate layer peels off from the glass, resulting in the disadvantage that it cannot be put to practical use.

Further, JP-A-59-166573 describes an adhesive whose main component is a (meth)acrylate compound having the following structural formula.

Structural formula: is said to be suitable as an adhesive for laminated glass.

However, since this compound has a hydroxyl group at the end, it tends to peel off from the glass. In particular, when a heat-cooling cycle test is performed, the intermediate cured product slightly peels off from the glass, causing a problem that thread-like peeling occurs in the laminated glass, making it impossible to put it to practical use.

Additionally, when recovering glass plates from products that have defects such as peeling during the manufacture of laminated glass, it is necessary to cut and separate the glass and the cured adhesive. However, in conventional adhesives, no improvements have been made that can solve the two problems of preventing the adhesive from peeling off from the glass as described above and facilitating the separation process. It wasn't.

Another issue with adhesives used for laminated glass is to be able to create a thick hardened layer of adhesive in order to ensure safety when the laminated glass breaks, and this issue is urgently needed. It is.

[Problems to be solved by the invention]

The present invention solves the conventional problems and provides a cured product that has excellent adhesion to glass and does not peel off due to residual stress during curing. This invention was developed to provide a glass adhesive that can be cut and separated from glass.

Another object of the present invention is to provide a glass adhesive suitable for bonding to glass in a thick film.

[Means for solving problems]

That is, the glass adhesive provided by the present invention has the following general formula (1) (wherein R4 and R2 each represent a hydrogen atom or a methyl group; R6 represents an alkyl group; n represents is an integer of 1 or more) (1 selected from the group
It is characterized by containing a species or two or more kinds of compounds and a photoinitiator (B) as main ingredients.

[Specific description and examples of the structure and effects of the invention] The radically polymerizable compound (~ is either polyethylene glycol or polypropylene glycol), which is the main component of the glass adhesive of the present invention, is alkoxylated at the terminal end,
The other end is (meth)acryloyloxylated and has a sentence structure, and this structure makes it photocurable, and the resulting cured product is resistant to internal stress due to shrinkage during curing and during heating or cooling. The resulting internal stress can be effectively removed, and peeling from the glass can be completely prevented. Moreover, the obtained cured product is colorless and transparent, and is suitable as an intermediate layer of laminated glass. Further surprisingly, the cured product of the glass adhesive of the present invention can be easily cut from glass. This has great advantages as described below. In other words, even if a defective product occurs due to minute scratches on the laminated glass obtained as a final product or minute air bubbles in the intermediately cured product, the product can be processed without damaging expensive cathode ray tubes, etc.
Moreover, by safely separating the intermediate cured product, it becomes possible to recover and reuse the glass.

In the general formula (I), R, and R2 are each a hydrogen atom or a methyl group, and R3 is a straight chain or branched alkyl group that may have a substituent. It's easy to get things. n is an integer greater than or equal to 1, but if n exceeds 25, it becomes wax-like or solid and becomes difficult to handle, which is not preferred.

In the present invention, one or more compounds of the group of radically polymerizable compounds (A) represented by the general formula (I) can be used, and for example, during synthesis, a plurality of compounds with different n A compound obtained in a mixed state of compounds (
5)) can be used.

The amount of the radically polymerizable compound (A) in the glass adhesive of the present invention is preferably 20% by weight or more.

Among the group of radically polymerizable compounds (A) used in the present invention, the compound represented by the formula (■): H30 is the most preferred, and has features such as being excellent in terms of safety such as skin irritation. There is.

In the glass adhesive of the present invention, various lanocal polymerizable monomers and oligomers other than the compound represented by the general formula (I) may be used to improve various performances required as an adhesive for glass. I can do it. For example, in order to improve the adhesion between the cured product and glass, 2-hydroxyethyl (meth)acrylate is used as a hydroxyl group-containing monomer, or (meth)acrylic acid is used as a carxyl group-containing monomer. It will be done. In order to improve the cohesive strength of the cured product, various polyfunctional monomers and oligomers are used as crosslinking components.

Furthermore, relatively low-cost general-purpose monomers, such as alkyl (meth)acrylates such as 2-ethyl (meth)acrylate, can be used in combination for Kostakun.

However, the amount of these monomers and oligomers used must be within a range that does not significantly impair the effects obtained by the present invention, and is preferably 70% by weight or less of the total amount of the glass adhesive.

It goes without saying that the radically polymerizable compound represented by the general formula (1) should be used within a range that does not impair the above-mentioned excellent properties obtained by filling and curing.

The photoinitiator (B) is an essential component for curing the glass adhesive of the present invention, and may be used alone or in combination. Specifically, benzyi/methyl ether, benzoin ethyl ether, benzoin zolobyl ether, benzoin-n-butyl ether, benzophenone, benyl dimethyl ketal, methyl phenyl glyoxylate, 2-hydroxy-2-methyl-1-phenylgulon-4- Examples include 1-one, 2-ethylanthraquinone, a mixed system of benzophenone and a tertiary amine, a mixed system of 2-chlorothioxanthone and a tertiary amine, etc., but in the case of the present invention, the curing speed is generally fast. It is more preferable to use a material that does not cause discoloration of the resulting cured product. For example, 2-hydroxy-2-methyl-1-phenylpropan-1-onato can be suitably used.

The amount of the photoinitiator (B) in the glass adhesive of the present invention is preferably 0.1 to 10% by weight.

In order to further improve the adhesion to glass, a silane coupling agent (gold) may be added to the glass adhesive of the present invention, which has these components (~, (B)) as main ingredients, or the final product, laminated glass. Addition of various dyes, pigments, etc. to impart design properties can be done depending on the application as long as various properties are not impaired.The surface of the Ti glass is pretreated with a silane casogling agent. By doing so, the adhesion between the intermediate cured product and the glass can be completely improved.

As the light source used for curing the glass adhesive of the present invention, lamps with a radiation wavelength of 200 to 450 mμ, such as low pressure mercury lamps, high pressure mercury lamps, xenon lamps, arc lamps, and gallium lamps, are effective.

In order to prevent peeling between the cured product and the glass, a low energy irradiation dose is used to reduce the internal stress caused by curing shrinkage.
Slow curing is generally preferred. In particular, laminated glass used in television cathode ray tubes, etc., is undesirable because if it is cured with high energy for a short period of time, it may cause microscopic unevenness in curing and easily peel off from the glass.
The irradiation energy is 10 at a wavelength of 365 nm.
- It is preferred to cure with a low irradiation energy of 1 or less. Further, heating after photocuring to remove internal strain and prevent separation between the intermediate cured product and the glass may be used as necessary.

In the following examples, the present invention will be explained in detail by way of examples, where "parts" means parts by weight.

Examples 1-10. Comparative Example 1.2 A laminated glass as shown in FIG. 1 was produced. First, rubber gaskets 2 measuring 3x5x5 were placed on the four corners of untreated glass (300x300x1), and glass 1 of the same size was stacked and pressed. Next, all four sides were wrapped with polyester adhesive tape and sealed to prevent the filling adhesive from leaking.

A photocurable filling adhesive 3 having the composition shown in Table 1 was injected between these two glass plates 1.1. After sealing the injection port with tape, apply Chemical Run
C) was irradiated for 10 minutes and cured. Table 1 shows the various performances of the obtained laminated glass. The laminated glass using the glass adhesive of the present invention had good adhesion to glass, cutting workability, and various other properties.

Example 11 Ethanol/water/7 run coupling agent A-1120 (
Nippon Unicar) = 90/10/1 (weight ratio) of untreated glass (3
00X300X1a+) were immersed, taken out, and air-dried to produce silane cuff-pulling treated glass. Thereafter, a laminated glass case was made in exactly the same manner as in Example 1, and then a photocurable filling adhesive (same as in Example 1) was injected. Subsequently, laminated glass was produced in exactly the same manner as in Example 1. The various properties of the obtained laminated glass were good as shown in Table 1.

Table-1 note) *1) Carpitol acrylate...One kind of radically polymerizable compound according to the present invention Structural formula: *2) NK ester M-90G (trade name)...Radical polymerizable compound according to the present invention A type of compound, Shin Nakamura Chemical Industry ■
Structural formula: *3) NK Ester M-230G (trade name): One of the radically polymerizable compounds according to the present invention, manufactured by Shin Nakamura Chemical Co., Ltd. Structural formula:

H30 *4) Glenmar PP-1000 (product name)...
Polyethylene glycol dimethacrylate, NOF■
Structural formula: % formula %) *5) Glenmar PE-350 (product name)...Polyethylene glycol monomethacrylate, NOF■
Structural formula: % Formula %) *6) NK Ester 3G (Product Name)...Polyethylene glycol dimethacrylate, Shin Nakamura Chemical Co., Ltd. Structural formula: *7) Guiyapeem UK-6035 (Product Name: Le...
Urethane acrylate, manufactured by Mitsubishi Rayon *8) A-174 (trade name)...silane coupling agent, manufactured by Union Carbide Structural formula: *9) Grocure-1173 (trade name)...photoinitiator, Structural formula manufactured by Merck & Co.: *10) Adhesiveness to glass O: No peeling from the glass, very good adhesion, Δ: Almost no peeling from the glass, good adhesion, ×: No peeling from the glass This always occurs and the adhesion is poor.

The heat-cooling cycle consists of cooling at -30°C for 30 minutes and heating at 85°C.
℃ for 30 minutes is defined as one cycle, and this means that this cycle is repeated 10 times.

*11) Cutting ability of cured product After photo-curing, a cutter was placed between the laminated glasses, and the difficulty of cutting the cured product was evaluated.

O: Easy to cut. △: Slightly difficult to cut.

*12) Cohesive force of cured product After photocuring, the cured product between the laminated glasses was taken out and evaluated by the appearance of breakage when pulled by hand.

◎:: Relatively strong, ○: Comparatively negative.

*13) Transparency of cured product 0: Good.

*14) Skin irritation ○：No, Δ: Yes.

*15) Injection workability Q: Possible to inject, Δ:: Not allowed.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of the simulated laminated glass produced in the example. ■...Glass plate, 2...Rubber seal, 3...Glass adhesive. Representative Patent Attorney Johei Yamashita

Claims (3)

[Claims] (1) The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 and R_2 each represent a hydrogen atom or a methyl group. R_3 represents an alkyl group. n is Representing an integer of 1 or more.) An adhesive for glass characterized by containing as main ingredients one or more compounds selected from the group of radically polymerizable compounds (A) and a photoinitiator (B). agent. (2) The amount of radically polymerizable compound (A) is 20 to 9
9.9% by weight, the amount of photoinitiator (B) is 0.1-10
The adhesive for glass according to claim (1), which is % by weight. (3) As the radically polymerizable compound (A), the following formula (I
I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ The adhesive for glass according to claim 1 or 2, which contains a compound represented by the following.