JPH0412734B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for adhering nylon resin, and more specifically, the present invention relates to a method for adhering nylon resin.

[Formula] Obtained by treating with an organic active halogen compound having a group (X represents a halogen) and then reacting polytetramethylene glycol with an isocyanate compound whose main component is 4,4'-diphenylmethane diisocyanate. A one-component moisture-curing adhesive made of a urethane polymer with an equivalent ratio of isocyanate groups/hydroxyl groups within a specific range, or a one-component moisture-curing adhesive made of a urethane prepolymer modified with a short-chain diol. This invention relates to a method for adhering nylon resin to be applied. [Prior art] Methods for adhering nylon fibers and resins include a method of adhering nylon fibers and rubber using resorcinol-formalin-rubber latex at a processing temperature of 150°C or higher, and a method of adhering nylon fibers and rubber at a processing temperature of 150°C or higher; Using a fiber solvent,
A co-cement method in which the nylon resin is bonded with heat and pressure at a temperature of 100°C or higher, or a bonding method where the nylon resin is bonded with the resin at a temperature higher than the melting point of the resin, e.g.
There are melt bonding methods that melt and bond materials at temperatures above 200℃, and we perform bonding work by taking advantage of the characteristics of each method. In addition, in order to improve the adhesion of nylon resin, etc., the surface of the adhesion interface can be treated with molten metal sodium, corona discharge, glow discharge, radiation, plasma irradiation, etc. prior to these adhesion.
Various treatment methods using ultraviolet rays, flame irradiation, hydrochloric acid, sulfuric acid, etc. have been used. [Problems to be Solved by the Invention] However, the above-mentioned bonding methods have in common that they require heating to obtain the bonding effect, and cannot be bonded to shapes or products that cannot be heat-treated. These methods cannot be used,
This method still has problems that need to be improved, such as requiring extra equipment, such as equipment for solvent evaporation, or requiring a long processing time. In order to solve this problem, the present inventor developed an isocyanate group/hydroxyl group obtained by reacting polytetramallene glycol with a specific molecular weight with an isocyanate compound whose main component is a 4,4'-diphenylmethane diisocyanate compound. We have proposed a one-component moisture-curing adhesive made of a urethane polymer with an equivalent ratio within a specific range, or a one-component moisture-curing adhesive made of a urethane prepolymer modified with a short-chain diol. This makes it possible to bond nylon resins such as 6-nylon and 6,6-nylon without the need for heating. However, even when the above adhesive is used, adhesion of nylon resins such as 10-nylon, 11-nylon, and 12-nylon to polyester fibers is still insufficient. In order to improve the adhesive strength of these nylon resins, etc., it is possible to treat the adhesive interface of the nylon resin with the above treatment method before applying the adhesive, but none of the above methods are industrially applicable. There were also safety and health issues, equipment issues, and usage issues. [Means for solving the problems] The present invention provides nylon resin, particularly 10-nylon,
The object of the present invention is to provide a method for adhering nylon resin such as 11-nylon and 12-nylon to suitably bond polyester fibers and the like. The present inventor first focused on the fact described in Japanese Patent Application Laid-Open No. 53-138480. JP-A No. 53-138480 discloses that for vulcanized rubbers that contain carbon-carbon unsaturated double bonds in their molecules due to their chemical structure,

It is stated that treatment with an organic active halogen compound having a bond (X is halogen) has a treatment effect. The present inventor found that organic active halogen compounds have a treatment effect even on the above-mentioned nylon resin, which does not have a carbon-carbon unsaturated double bond (aliphatic) in its molecule due to its chemical structure. By treating the adhesive interface of nylon resin such as nylon with an organically active halogen compound and then applying the above adhesive, the nylon resin can be bonded with high adhesive strength at room temperature or at a processing temperature of 80°C or less. We have discovered that this can be done, and have arrived at the present invention. In other words, the present invention incorporates the adhesive interface of nylon resin into the molecule.

[Formula] After treatment with an organic active halogen compound having a group (X represents a halogen), an isocyanate compound containing polytetramethylene glycol and 4,4'-diphenylmethane diisocyanate with an average molecular weight of 700 to 1800 as main components. The equivalent ratio of isocyanate group/hydroxyl group is 1.3 to 2.0.
A one-component moisture-curing adhesive made of a urethane prepolymer obtained by reacting the urethane prepolymer so that the urethane prepolymer reacts with This method of bonding nylon resin is characterized by applying a one-component moisture-curing adhesive made of a urethane prepolymer modified with a chain diol. The nylon resin used in the present invention is not particularly limited, but is particularly suitable for 10-nylon, 11-nylon, 12-nylon, etc., for which sufficient adhesive strength cannot be obtained even if only the adhesive used in the present invention described below is used. used for. In the present invention, the adhesive interface of the nylon resin is

[Formula] Treatment with an organic halogen compound having a bond. Examples of the organic halogen compounds used here include halogenated succinimides such as N-bromsuccinimide, halides of isocyanuric acid such as trichloroisocyanuric acid and dichloroisocyanuric acid, and halogenated hydantoins such as dichlorodimethylhydantoin. Among these, trichloroisocyanuric acid is preferred. It is preferable to use an appropriate soluble solvent such as methyl ethyl ketone or ethyl acetate as an organic solvent to adjust the concentration of the organic halogen compound to 2 to 10%. In the present invention, a one-component moisture-curing adhesive is then applied to the nylon resin. The one-component moisture-curing adhesive (hereinafter simply referred to as adhesive) used here is obtained by reacting polytetramethylene glycol with an isocyanate compound whose main component is 4,4'-diphenylmethane diisocyanate. It consists of a urethane prepolymer having an isocyanate group/hydroxyl group equivalent ratio within a specific range, or a urethane prepolymer modified with a short chain diol. Polytetramethylene glycol (PTMG) is used as a polyol to form this urethane polymer.
Use. Among polyols, PTMG has the best adhesion to nylon resin. In the present invention, it is also possible to use PTMG whose ends are modified with propylene oxide or the like. The average molecular weight of PTMG is in the range of 700 to 1800, preferably 800 to 1700;
Adhesives using PTMG have an adhesive force of 5 kg/in or more when bonded to nylon resin at room temperature. When the average molecular weight of PTMG is less than 700 or more than 1800, the adhesive strength decreases. Furthermore, this PTMG
The average molecular weight of is a value calculated from the hydroxyl value. On the other hand, as the isocyanate compound forming the urethane prepolymer, an isocyanate compound containing 4,4'-diphenylmethane diisocyanate as a main component is used. There are various compounds containing isocyanate groups (-NCO), but aliphatic isocyanate compounds are not suitable for moisture-curing adhesives because they react slowly with moisture in the atmosphere, and they also have poor heat resistance. Even if you look at it, it's not enough. On the contrary,
As aromatic isocyanate compounds, tolylene diisocyanate (TDI), bitolylene diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), 4,4'-diphenylmethane diisocyanate (MDI), etc. are commonly used. However, like aliphatic isocyanate compounds, TDI reacts slowly with atmospheric moisture, making it unsuitable for moisture-curing adhesives, while NDI, TODI, etc. are expensive and therefore impractical. Also NDI
When used as an adhesive, it lacks storage stability and is not practical. Therefore, in the adhesive used in the present invention, an isocyanate compound (hereinafter referred to as , collectively referred to as MDI). This MDI may be pure MDI with a high purity of about 100%, or modified MDI partially decarboxylated and condensed, such as Isonate 143L manufactured by Kasei Upjiyon Co., Ltd. or crude MDI shown by the chemical formula below. (n=0, 1 or 2), but hydrogenated MDI is not preferable from the point of view of safety and health. In addition, in the present invention, in the adhesive made of the urethane polymer, a part of the MDI is TDI,
It is also possible to use it by replacing it with TODI, NDI or an aliphatic isocyanate compound. The adhesive used in the present invention is PTMG and
The equivalent ratio of isocyanate groups/hydroxyl groups in the urethane prepolymer obtained by reacting MDI is 1.3 to
2.0, preferably 1.4-1.9. A urethane prepolymer obtained by reacting a polyol with an isocyanate compound is usually obtained by reacting the isocyanate group/hydroxyl group in an equivalent ratio of 1.9 to 2.5. Moisture-curing adhesives have a curing mechanism in which atmospheric moisture reacts with isocyanate groups to form urea bonds and generate carbon dioxide gas. When a large amount of carbon dioxide gas is generated, or when carbon dioxide gas is rapidly generated, the gas dissipates slowly and remains as bubbles in the adhesive layer, making it impossible to obtain sufficient adhesive strength.
Methods for eliminating air bubbles include reducing the isocyanate groups in the prepolymer, ie, reducing the amount of gas generated, and reducing free MDI, ie, reducing the rapid amount of gas generated. In addition, addition of carbon dioxide absorbents, fillers, plasticizers, solvents, etc. is also an effective method. Moisture-curing urethane prepolymer has a free MDI content of 1% of the total MDI.
It is desirable to do the following. One method for reducing the amount of free MDI is to reduce the isocyanate group/hydroxyl group equivalent ratio. The method of reducing the equivalent ratio is also effective in reducing the number of active isocyanate groups. Therefore, in the claimed invention,
The upper limit of the equivalence ratio is set to 2.0, preferably 1.9. In addition, if this equivalent ratio is too small, the molecular weight of the urethane prepolymer becomes too large than necessary, which inevitably increases the viscosity and makes it difficult to handle as an adhesive. This results in poor wetting of polyamide resin, etc., and sufficient adhesion cannot be obtained.
Also, since the amount of free isocyanate groups is reduced, the amount of urea bonds formed during the curing reaction is reduced. Comparing urethane bonds and urea bonds, urea bonds contribute more to heat resistance, so a decrease in the amount of urea bonds means a decrease in heat resistance. Therefore, in the present invention, the lower limit of the equivalent ratio is set to 1.3, preferably 1.4. In the adhesive used in the present invention, by further modifying the urethane prepolymer obtained as described above with a short chain diol, the reaction shown in the following formula proceeds, increasing the adhesive strength to the resin. can be improved. (In the above formula, HO-B-OH represents a short chain diol, and OCN-R ₁ -NCO and OCN-R ₂ -NCO represent the above-mentioned urethane prepolymers, respectively.) While this reaction is proceeding, free MDI
When present, short chain diols react preferentially, so the presence of short chain diols also has the function of removing free MDI. When carrying out this modification, the molar ratio of PTMG and short chain diol is important. In other words, the presence of short chain diol has an effect of improving adhesive strength, and increasing the amount of short chain diol reduces adhesive strength, and the molar ratio of short chain diol/PTMG is 0.5.
As it approaches , the adhesive strength becomes the same as before modification. In the relationship between the two, as the molar ratio becomes sufficiently large, the molecular weight of the prepolymer begins to increase and becomes a polymer around 1.0, so that the moisture curing function is lost. Therefore, when modifying with short chain diol, the molar ratio of short chain diol/PTMG should be set to 0.5.
Below, it is preferably 0.4 or less. The short-chain diols used here include diols with a molecular weight of at least about 400 or less, such as ethylene glycol, 1,4-butanediol, diethylene glycol, beta-hydroxyethyl benzoate, beta-hydroxyethyl terephthalate, and modified products or mixtures thereof. It's okay to be. Among these short chain diols, 1,4
-butanediol is most preferred. The adhesive used in the present invention obtained in this way is treated with a solvent that does not react with isocyanate groups, such as methyl ethyl ketone (MEK), toluene, ethyl acetate, cellosolve acetate, thinner, and hexane, for degreasing and viscosity adjustment. It is desirable to use it diluted. Also, if desired,
It is also optional to add various additives. As explained above, the nylon resin bonding method of the present invention is particularly suitable for bonding products that cannot be pressurized, such as nylon tubes made of 11-nylon for plastic hoses, and reinforcing fibers such as polyester fibers. . [Examples] The present invention will be specifically described below based on Examples and Comparative Examples. Examples 1 to 4 and Comparative Examples 1 to 8 11-nylon (trade name: BENSO) was used as the adherend.
A 2 mm thick in-die extension sheet of P-40TL (manufactured by Toray Industries, Inc.) was prepared. Trichloroisocyanuric acid diluted with ethyl acetate and having a concentration of 3% was applied to this adhesive interface with a brush, and air-dried for about 5 minutes at 20° C. and 65% relative humidity to obtain a trichloroisocyanuric acid-treated adherend. Next, 100 kg of PTMG (trade name Terratan 650, manufactured by DuPont) with an average molecular weight of 670 was added to the reaction vessel.
After adjusting the temperature to 50℃, pure MDI66.6Kg (NCO/
OH equivalent ratio = 1.8) was added. A rapid exothermic reaction
After 1 hour had passed and the reaction had subsided, the reaction was further carried out at 80°C for 5 hours to obtain a urethane prepolymer.
10% by weight of dry methyl ethyl ketone was added to the urethane prepolymer thus obtained and mixed uniformly by stirring to obtain Adhesive-1. This Adhesive-1 was applied with a brush to the above-mentioned trichloroisocyanuric acid-treated adherend and to the adherend not treated with trichloroisocyanuric acid, and a polyester fiber fabric was lightly pressed on top of the adherend, and then the adhesive was applied for 20 minutes.
It was left to stand naturally at ℃ for 7 days (Comparative Examples 1 and 2). Furthermore, as PTMG, it has an average molecular weight of 850.
PTMG (product name PTG-100, manufactured by Nippon Polyurethane Co., Ltd.), PTMG (product name PTG-) with an average molecular weight of 1100
200, manufactured by Nippon Polyurethane Co., Ltd.), with an average molecular weight of 1300.
PTMG (product name PTG-300, manufactured by Nippon Polyurethane Co., Ltd.), PTMG (product name PTG-) with an average molecular weight of 1500
400, manufactured by Nippon Polyurethane Co., Ltd.), with an average molecular weight of 2100.
A urethane prepolymer was obtained in the same manner as in Comparative Example 1 except for using PTMG (trade name PTG-500, manufactured by Nippon Polyurethane Co., Ltd.), and 10% by weight of dry methyl ethyl ketone was added and mixed uniformly by stirring to obtain Adhesive-2.
~6. This adhesive-2-6 was used
The average molecular weight of PTMG used in adhesive-1
Table 1 shows the average molecular weight of PTMG. These adhesives-2 to 6 were used in the same manner as in Comparative Examples 1 to 2.
The above trichloroisocyanuric acid-treated adherend and non-trichloroisocyanuric acid-treated adherend were coated with a brush, a polyester fiber fabric was lightly pressed onto this, and the mixture was allowed to stand at 20°C for 7 days. Examples 1-3 and Comparative Examples 3-8). After allowing the film to stand for 7 days, a peel test was conducted. The peel test was performed at a tensile speed of 50 mm/min for 20
The experiments were carried out under conditions of ℃. The results are shown in Table 1 and
As shown in the figure.

【table】

[Table] As shown in Table 1, the adherends treated with trichloroisocyanuric acid exhibit higher adhesive strength values than the adherends not treated with trichloroisocyanuric acid. Furthermore, adhesive strength has a very close relationship with the average molecular weight of PTMG used, and suitable adhesive strength can be obtained when the average molecular weight of PTMG is in the range of 700 to 1,800. Examples 5 to 8 and Comparative Examples 9 to 18 100 Kg (76.9 mol) of PTMG with a molecular weight of 1300, pure
To 149.6 kg of adhesive-4 used in Example 3 and Comparative Example 5 obtained from 34.6 kg (138.4 mol) of MDI and 15 kg of dry methyl ethyl ketone, dehydrated 1 with a molecular weight of 90,
4-butanediol 0.5Kg (5.6mol, K=0.07),
1.0Kg (11.1mol, K=0.14), 2.0Kg (22.2mol,
K=0.29), 2.8Kg (31.1mol, K=0.40), 3.5Kg
(38.9 mol, K=0.51), 4.8Kg (53.3 mol, K=
0.69) and 6.2 Kg (68.9 mol, K=0.87) were added, stirred and mixed at room temperature (20 to 30°C) for 60 minutes, and then allowed to stand naturally for 24 hours to fully react, to obtain an adhesive. Note that the K value is the molar ratio of 1,4-butanediol/polytetramethylene glycol. Using the trichloroisocyanuric acid-treated adherend used in Comparative Examples 1 and 2 and the adherend not treated with trichloroisocyanuric acid, each adhesive obtained as described above was applied with a brush, and Comparative Example 1 A peel test was conducted using the same method as above. The results are shown in Table 2 and Figure 2. Furthermore, the results of Example 3 and Comparative Example 5 using Adhesive-4 to which 1,4-butanediol was not added are also shown in Table 2 and FIG. 2 for reference.

[Table] As shown in Table 2 and FIG. 2, in this bonding as well, the adherend treated with trichloroisocyanuric acid shows a higher value of adhesive strength than the adherend not treated with trichloroisocyanuric acid. Further, the molar ratio of 1,4-butanediol/polytetramethylene glycol has a great influence on the adhesive force, and when the molar ratio is 0.50 or less, it contributes to an improvement in the adhesive force. In Table 2, Comparative Examples 15 and 16 were not completely cured and remained sticky. Furthermore, Comparative Example 17 and Comparative Example 18 were not cured. [Effects of the Invention] As explained above, the method of adhering nylon resin of the present invention is particularly suitable for bonding 10-nylon, 11-nylon, 12-nylon, etc.
- High adhesion to nylon resins such as nylon is possible in the temperature range from low temperatures to about 80°C or below, where no residual strain occurs in the resin. Adhesion of reinforcing fibers to parts where pressure cannot be applied, such as 11-nylon tubes of plastic hoses, etc.
This exhibits a great effect on adhesion between the reinforcing fibers and the cover material.

[Brief explanation of drawings]

Figure 1 shows PTMG in Examples and Comparative Examples.
Graph showing the relationship between average molecular weight and adhesive strength, 2nd
The figure is a graph showing the relationship between the molar ratio of 1,4-butanediol/polytetramethylene glycol and adhesive strength in Examples and Comparative Examples. The solid line is for the adherend treated with trichloroisocyanuric acid, and the dotted line is for the adherend not treated with trichloroisocyanuric acid. The results using the following adherends are shown.

Claims (1)

[Claims] 1. After treating the adhesive interface of the nylon resin with an organic active halogen compound having a [formula] group (X represents a halogen) in the molecule, polytetramethylene glycol having an average molecular weight of 700 to 1800 is treated. A one-component moisture-curing type made of a urethane prepolymer obtained by reacting an isocyanate compound containing 4,4'-diphenylmethane diisocyanate as a main component such that the equivalent ratio of isocyanate groups to hydroxyl groups is 1.3 to 2.0. A one-component moisture-curing adhesive made of a urethane prepolymer modified with a short chain diol such that the molar ratio of short chain diol/polytetramethylene glycol was 0.5 or less was applied to the adhesive or the urethane prepolymer. A method for adhering nylon resin. 2. The method of bonding nylon resin according to claim 1, wherein the nylon resin is 10-nylon, 11-nylon, or 12-nylon.