JPH02197579A - Pretreating agent for electroless plating of polyamide resin - Google Patents

Abstract

PURPOSE:To improve the adhesion of a plating film to polyamide resin by pretreating the resin with an aq. soln. contg. the sulfonated product of a specified condensate of formaldehyde before catalytic activation when the surface of the resin is electroless-plated with a metal. CONSTITUTION:When a member of polyamide resin such as 6-nylon is electroless-plated with a metal such as Cu, Ni or Co, the member is pretreated by coating with an aq. soln. contg. at least one kind of compd. selected among the sulfonated product of a condensate of formaldehyde with a compd. represented by formula I such as 2,2'-dihydroxydiphenyl ether, a condensate of formaldehyde with the compd. represented by the formula I and naphthalenesulfonic acid, the sulfonated product thereof and tannic acid. The pretreated resin is sensitized with a stannous chloride soln. acidified with hydrochloric acid as a sensitizer soln. as usual. The sensitized resin is activated with an activator soln. contg. ions of a noble metal such as Pd, Au or Ag and then electroless plating is carried out. A plating film of Cu, etc., having superior adhesive strength can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electroless plating pretreatment agent for polyamide resins.

Conventional technology and its problems In order to perform electroless plating of copper, nickel, cobalt, etc. on an object to be plated that does not have catalytic activity, it is necessary to attach a catalytic substance to the object to impart catalytic activity. is necessary. The following methods are known as such methods.

(a) A method in which the surface of the object to be plated is sensitized with a sensitizer solution consisting of an acidic hydrochloric acid solution of stannous chloride, and then activated with an activator solution containing noble metal ions such as palladium, gold, and silver.

(b) A method of immersing in a catalyst liquid, which is a palladium-tin colloidal liquid, and then activating it with an accelerator liquid.

However, even if electroless plating is performed after the above activation treatment (a) or (b) is applied to a normal polyamide resin, the adhesion of the plating film is poor and it cannot be put to practical use. Therefore, when performing electroless plating on polyamide resin, a plating-grade resin molded with acid-soluble particles contained in the resin is used, and this is etched with an acid treatment agent such as hydrochloric acid or sulfuric acid to form a plating layer in the resin. The adhesion of the plating film is improved by the so-called anchoring effect by dissolving the acid-soluble particles to form holes in the resin, then attaching a catalyst substance and performing the plating process.

However, for polyamide resins other than plating grade that do not contain acid-soluble particles, the adhesion of the plating film cannot be improved by the above method.

Furthermore, there are no plating-grade polyamide fibers on the market, and even if they were, acid etching would cause the polyamide fibers to become severely brittle and shrink, impairing the original texture and strength of the fibers. There's a problem. Furthermore, when etching is performed using hydrochloric acid or sulfuric acid, there are problems such as restrictions on the equipment that can be used due to the low pH.

Means for Solving the Problems In view of the problems of the prior art as described above, the inventor of the present invention
As a result of extensive research, we have found that at least one of a sulfonated product of a formaldehyde condensate of a specific diphenyl compound, a formaldehyde condensate of the diphenyl compound and naphthalene sulfonic acid or a sulfonated product thereof, and tannic acid.
It has been found that when pretreatment for electroless plating is performed using an aqueous solution containing seeds, it is possible to form an electroless plating film with good adhesion on a polyamide resin. In addition, especially when pre-treating polyamide fibers using the above-mentioned pre-treatment agent, it is possible to form an electroless plating film with good adhesion without causing any shrinkage or embrittlement of the fibers. We have discovered that this is possible and extremely useful.

That is, the present invention provides: (i) a sulfonated formaldehyde condensate of a compound represented by the general formula H3 (wherein X represents oSso2 or -C-); (11) a compound of the above general formula (I); The present invention relates to an electroless plating pretreatment agent for polyamide resin, which contains at least one of a formaldehyde condensate with naphthalene sulfonic acid or a sulfonated product thereof, and (iii) tannic acid.

The polyamide resin to which the pretreatment agent of the present invention is applied is a polymer compound having an amide bond (-CONH-), and includes linear polyamides such as 6-nylon, 6,6-nylon, 11-nylon, etc. can be mentioned, but
In addition, resins having a cyclic structure or a heterocycle such as boriazine synthetic resin, or mixed resins containing these may also be used. These may be in the form of molded products, films, etc., or may be in the form of textile products such as threads, knitted fabrics, nonwoven fabrics, etc.

The pretreatment agent for electroless plating used in the present invention includes (i) a sulfonated formaldehyde condensate of a compound represented by the general formula (wherein,
The active ingredient is a formaldehyde condensate of the compound () and naphthalene sulfonic acid or a sulfonated product thereof, and (iii) tannic acid. The compounds (i) to (iii) above can be used alone or in combination.

Specific examples of the compound of formula (I) used in the present invention include 2,2'-dihydroxydiphenyl ether, 2,4'-dihydroxydiphenyl ether, 4
, 4'-dihydroxydiphenyl ether, 2,2'
-dihydroxydiphenylsulfone, 2.4'-dihydroxydiphenylsulfone, 4.4'-dihydroxydiphenylsulfone, 2.2'-isopropylidenediphenol, 2.4'-isopropylidenediphenol, 4,4' -isopropylidene diphenol, etc.

The sulfonated formaldehyde condensate of the compound of general formula (1) shown in (1) above can be obtained, for example, by the following method. That is, compound 1 of formula (I).
Add a solvent, for example, acetic anhydride to 0 mol, and make 90-130
Sulfonation is carried out at a temperature of approximately 0.3 to 8 mol of sulfuric acid for approximately 2 hours. Next, about 0.5 to 3.0 mol of formaldehyde is added dropwise at about 75 to 110° C. over about 3 hours to cause condensation, and then the pH is adjusted to about 2 to 7 with an alkali such as aqueous ammonia or caustic soda. Incidentally, sulfonation may be performed after condensation with formaldehyde.

Further, the formaldehyde condensate of the compound of general formula (I) and naphthalene sulfonic acid or the sulfonated product thereof shown in (ii) above can be obtained, for example, by the following method. That is, a total of 1.0 mol of the compound of general formula (I) and β-naphthalene sulfonic acid (former: latter (molar ratio)
-1:0.3 to 1:5 degree) to water, sulfonated using about 0.3 to 6 mol of sulfuric acid as necessary for about 2 hours, and then heated to about 75 to 110°C with no formaldehyde.
．． After about 5 to 3.0 mol is added dropwise over about 3 hours and condensed, the pH is adjusted to about 2 to 7 with an alkali such as aqueous ammonia or caustic soda.

Incidentally, sulfonation may be performed after condensation with formaldehyde.

The compound (i) or (ii) above has a weight average molecular weight of 1
It is preferably about 000 to 30,000, more preferably about 1
It is about 500 to 15,000. The weight ratio of carbon atoms to sulfur atoms is preferably about 0.6:1 to 25:1, more preferably about 1:1 to 15:1.

The pretreatment agent of the present invention is usually used as an aqueous solution containing at least one of the above-mentioned compounds (i), (ii), and (iii) as an active ingredient. The concentration of the active ingredient in the aqueous solution is not limited as it varies somewhat depending on the type and form of the polyamide resin used, but it is usually 0.01 to 20.
It is appropriate to set it to about 0 g/ρ.

When the polyamide resin to be treated is in the form of fibers, the above-mentioned active ingredient is used in % by weight based on the weight of the fibers (oow
, f,) is preferably about 0.1 to 200%, more preferably about 1 to 100%. o, w
If , f is less than 0.1%, the adhesion of the plated material will not be improved sufficiently, while if it exceeds 200%, a skip phenomenon in which the plating becomes mottled tends to occur, which is not preferable.

Bath ratio (weight ratio of treatment liquid to object to be treated) is 1:20~
It is appropriate to set it to about 1:1000, and 1:
100-1: It is preferable to set it as about 500.

The treatment method using the pretreatment agent of the present invention is not particularly limited,
The treatment may be carried out by a conventional dipping method, padding method, coating method, spraying method, etc. It is appropriate that the pretreatment agent aqueous solution has a pH of about 2 to 7, preferably about 2 to 7.

Pretreatment by the immersion method is performed at a treatment temperature of 40 to 130℃, for example.
This can be carried out by immersing it in an aqueous pretreatment agent solution at a temperature of about 80 to 110 degrees Celsius for about 1 to 120 minutes, preferably about 10 to 40 minutes. If the treatment temperature is lower than 40° C., the pretreatment agent will not be sufficiently adsorbed to the polyamide resin, and the adhesion of the plated object will not be sufficiently improved, which is not preferable.

As an example of a padding method, a pretreatment agent aqueous solution is used to
After padding at ~40°C, squeeze using a mangle so that the amount of liquid attached to the resin is around 30-200% by weight, dry, and dry at around 100-200°C for 30 seconds to 60%.
A method of performing dry heat treatment or steam treatment for about a minute can be shown.

As the steam treatment method, methods using ordinary pressure steam, high pressure steam (HP), high temperature steam (HT) using normal temperature superheated steam, etc. can be applied.

When processing by a coating method or a spray method, as in the padding method, the temperature is 30°C at about 100 to 200℃ after treatment.
It is preferable to perform a drying process or a steam process for about seconds to 60 minutes.

By pretreating the polyamide resin by the method described above, the pretreatment agent is uniformly adsorbed onto the resin. After that, a catalyst is applied according to a conventional method, and then the plate is immersed in an electroless plating solution, thereby forming a plated film with good adhesion.

The catalyst application step can be carried out according to a conventional method (for example, it can be carried out by the following method.

(a) The surface of the object to be plated is sensitized with a sensitizer solution consisting of an acidic hydrochloric acid solution of stannous chloride, and then activated with an activator solution containing noble metal ions such as palladium, gold, and silver.

(b) After being immersed in a catalyst liquid, which is a palladium-tin colloidal liquid, it is activated with an accelerator liquid.

The electroless plating treatment may be carried out according to a conventional method using various known electroless plating solutions. Examples of metals that can be electrolessly plated include copper, nickel, cobalt, silver, platinum, gold, and alloys thereof.

Effects of the Invention By using the pretreatment agent of the present invention, it is possible to easily form a plating film with good adhesion to polyamide resins, which conventionally had poor adhesion, without using special plating grade resins. can be formed. In particular, when applied to polyamide fibers, shrinkage of the fibers,
Since it is possible to form a plating film with good adhesion without causing embrittlement, it is extremely useful.

Furthermore, compared to pretreatment methods using hydrochloric acid or sulfuric acid, since the pH of the pretreatment agent is higher, this method is advantageous in that the range of use of equipment materials can be expanded.

Example Hereinafter, the present invention will be explained in more detail by showing examples.

Example 1 A 6-nylon taffeta cloth 1010×10 was soaked in the pretreatment agent shown in Table 1 at a bath ratio of 1:100, and then 100×10
Dry at °C. Next, stannous chloride 16g/Ω, palladium chloride 0.2g/ρ, hydrochloric acid 15g/Ω, and common salt 1.50g
/fl for 5 minutes at 25°C, followed by washing with water, followed by immersion in an accelerator solution of 100 ml of concentrated sulfuric acid at 25°C for 2 minutes, washing with water, and drying.

Next, 2 g/! of nickel chloride! 2. Sodium citrate 30g/A, sodium hypophosphite 15g/ρ, ammonium chloride 30g/ρ and aqueous ammonia 15aQ#
Using an electroless nickel plating solution consisting of the following, it was immersed in the plating solution at 40° C. for 5 minutes, washed with water, and dried.

For each sample obtained by the above method, the nickel deposition rate,
The results of measuring the surface resistance value, fiber shrinkage rate, and adhesion are
Shown in the table. The test method is as follows.

O nickel adhesion rate (%): The weight increase rate after nickel plating was determined.

0 Surface resistance value (Ω): Measured using a surface resistance meter (Laresta) manufactured by Mitsubishi Yuka ■.

0 Fiber shrinkage rate (%): It was expressed as the area loss rate (%) before and after immersion in the pretreatment liquid.

0 Adhesion: After pasting the double-sided tape on the plating cloth, use the Suga Test Machine■
Rub it 10 times with a manufactured friction tester, peel off the double-sided tape, and
The degree of peeling was examined.

×・・・Full peeling, Δ・・・Partial peeling, O
...The results of better or better indicate that by using the pretreatment agent of the present invention, a nickel plating film with good adhesion can be formed on the nylon fibers with almost no shrinkage of the fibers.

Example 2 10×10 cd of 6.6-nylon taffeta cloth were heated at 100°C in the pretreatment solution shown in Table 3 (bath ratio 1:100), respectively.
After being immersed in water for 20 minutes, it was dried at 100°C. Next, it was immersed in the same catalyst treatment solution as in Example 1 at 30° C. for 10 minutes, washed with water, then immersed in an accelerator solution consisting of 100 mQ/J2 of concentrated hydrochloric acid at 25° C. for 2 minutes, washed with water, and dried.

Next, copper sulfate 8g/Ω, formalin 8−/Ω, EDTA2
5 g/Ω, caustic soda 10 g/A and potassium ferrocyanide 1 g/A in an electroless copper plating solution.
After immersing at ℃ for 20 minutes, it was washed with water and dried.

The copper adhesion rate, surface resistance value, fiber shrinkage rate, and adhesion of each sample obtained by the above method were measured and the results are shown in Table 4 below. For comparison, the measurement results for a sample (Comparison Field 6) which was subjected to electroless copper plating in the same manner as the above method without being immersed in the pretreatment liquid are also shown.

As can be seen from the results in Table 4, a copper plating film with good adhesion can be formed by performing a pretreatment for electroless copper plating using the pretreatment agent of the present invention.

Example 3 4.4' as a pretreatment agent for nylon resin molded products
-Dihydroxydiphenylsulfonesulfonic acid formaldehyde condensate (molecular weight 1500, C: S-2,9
: 1) 0.3g/! Electroless nickel plating was performed in the same manner as in Example 1 using 2 aqueous solution. As a result, a nickel plating film with good adhesion was formed on the nylon resin molded product. On the other hand, the adhesion of the plating film was insufficient in the sample obtained by applying the catalyst and performing electroless plating without immersing the sample in the aqueous solution of the pretreatment agent.

(that's all)

Claims (1)

[Claims] (1) (i) Formaldehyde of a compound represented by the general formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, X represents O, SO_2 or ▲There are mathematical formulas, chemical formulas, tables, etc.▼) A polyamide characterized by containing at least one of a sulfonated product of a condensate, (ii) a formaldehyde condensate of the compound of general formula (I) and naphthalene sulfonic acid or a sulfonated product thereof, and (iii) tannic acid. Electroless plating pretreatment agent for resins.