KR890002373B1 - Process for the preparation of hat - melt adhesives - Google Patents

Abstract

Heat-melt adhesives are prepd. by (i) blending polyamide copolymer 70-95 wt.% (obtd. from polymg. epsilon-caprolactam 20-65 wt.%, aminododecanic acid 20-65 wt.% and hexomethylenediamineadipate 10-50 wt.% in the presence of water at 200-300 deg.C) and ionomer resin 5- 30 wt.% and (ii) compounding by twin screw extruder at 180-200 deg.C and at 180-250 RPM. The adhesive has a good water resisting property and is soluble in alcohol group solvent. It is useful for bonding metal with a fabric or nonwoven sheet.

Description

Method for producing hot melt adhesive based on polyamide homopolymer or copolymer

The present invention relates to a method for producing a hot melt adhesive based on a polyamide homopolymer or copolymer.

Manufacturing hot melt adhesive

(1) Method for producing hot melt adhesive comprising polyamide 6,66,610,12 homopolymer as a basic component (Japanese Patent Publication No. 48-24812, 48-25426)

(2) a method for producing a hot melt adhesive based on polyamide 6/66/610 copolymer (US Pat. No. 2,420,455); and

(3) Manufacturing method of hot melt adhesive comprising polyamide 6/66/12 copolymer as a basic component: British Patent 1,168,404, Japanese Patent Publication 52-910401, 44-19868).

However, the copolyamide produced by the above method has a high melting point and its use is limited. As can be seen from the following nylon structure (formula), the larger the chemical repeating unit, that is, the smaller the number of amide groups and the confused the structure, the lower the crystallinity. The reason is that the strength of the hydrogen bond is weakened, so the crystallinity is lowered and the melting point is lowered.

In addition, when the copolymer is more homogeneous than the homopolymer, the number of amide groups is further reduced and the hydrogen bond is weakened, thereby lowering the melting point and facilitating the process. However, the homopolymer or copolymer is limited in its use because of its high melting point and hardness due to its high crystallinity. In particular, such copolymerized polyamides are required in melting fields, adhesive strength, water resistance, and the like in the fields required for hot melt adhesives, for example, fiber bonding and metal bonding by hot press.

In addition, since polyamide is generally high in crystallinity, it is necessary to increase the adhesive strength by quenching the means such as quenching after bonding. The reason for this is because the crystallinity is high. Since the adhesive strength is low, a means such as quenching is necessary. In practice, however, this process has been extremely complicated from an industrial point of view.

As described above, various conventional copolymerized polyamides have a lot of amide bonds, i.e., hydrogen bonds have a high melting point and high crystallinity, and thus have high elasticity and high crystallinity.

Therefore, the conventional copolymer polyamide is known to be a hot melt adhesive, but as described above, there is a disadvantage in that the adhesive strength at low temperatures due to poor water resistance and lack of elasticity has a disadvantage in use as an adhesive.

The present invention is an adhesive by aligning co-polyamide and iono resin with ε-caprolactam or ε-aminocaproic acid and amino dodecanoic acid or lauryllactam, hexamethylenediamine and adipic acid as basic components. It is related with the manufacturing method of this improved hot melt adhesive.

Inherently required properties of hot melt adhesives are 1) low melting point (or softening point), strong adhesive strength, 2) good water resistance, no weakening of adhesive strength in wet state, and 3) resistance to fiber Excellent chemical property, 4) It is required that the adhesive strength does not decrease even at low temperature.

The present inventors have completed the present invention as a result of studying the hot melt to improve the disadvantages of the prior art to provide a method for producing a hot melt adhesive that satisfies the properties required for the hot melt adhesive.

That is, the present invention is composed of ε-caprolaltam or ε-aminocatonic acid and aminododecanoic acid or lauryllactam, hexamethylenediamine and adipic acid as basic components, and the mixed component is present in the presence of water and a catalyst. It is an object to provide a method for producing a hot-melt adhesive with improved adhesiveness by preparing a copolymerized polyamide and compounding the copolymerized polyamide and ionomer resin.

The present invention is described in detail as follows.

The present invention provides about 20-65% by weight of ε-caprolactam or ε-aminocaproic acid, about 20-65% by weight of aminododecanoic acid or lauryllactam, about 10-50% by weight of hexamethylenediamine and hexamethylene Copolymer polyamide is obtained by mixing the diamine component with equimolar equivalents of adipic acid as a basic component and pressing the mixture component under water, alcohol, amine, organic acid, etc., or heating to 200-300 ° C. under normal pressure. 70-95% by weight of copolymerized polyamide and 5-30% by weight of ionomer resin are compounded (alloy) to produce a hot melt adhesive with improved adhesion.

The present invention is described in more detail as follows.

The present invention is based on about 20-65% by weight of aminododecanoic acid or lauryllactam by about 20-65% by weight of ε-caprolactam or ε-aminocaproic acid, by hexamethylenediamine component and equimolar equivalents of adipic acid. To prepare a copolymerized polyamide by mixing as a component and to prepare a mixture of 70-95% by weight of the prepared copolymerized polyamide and 5-30% by weight of ionomer resin, the conventional 6/66/12 copolymerized polyamide alone Unlike use, it is a method of alloying rubber-based ionomer resin.

In this case, the polyamide 6/66/12 copolymer is prepared by pressurizing the mixed component under water, a catalyst such as alcohol, amine, organic acid or the like at 200-300 ° C. at normal pressure.

As a method of obtaining the copolymerized polyamide by polymerizing the basic components of the present invention, a known polymerization method may be applied, and as the catalyst to be added, an organic acid or an amine is added as a molecular weight regulator, and additionally a dye or an antioxidant is added. It is also possible.

In addition, the mixed component is obtained by adding the above catalyst and pressurizing at a temperature of 200-300 ° C. in the presence of water or polymerizing under normal pressure to obtain copolymerized polyamide. 70-95% by weight of the obtained copolymerized polyamide and 5-30% by weight of ionomer resin are prepared by compounding with a twin screw extruder to improve the adhesion.

Compounding conditions are the twin screw extruder with the temperature of zone 1: 200 ℃, zone 2: 190 ℃, zone 3: 180 ℃, zone 4: 180 ℃, zone 5: 200 ℃ 180-250 rpm cooling water tank. Pelletized to produce pellets. Various additives In compounding, various additives such as antioxidants, plasticizers and lubricants may be added.

If the ionomer resin content is less than 5% by weight, the content is small as in the case of using the copolymerized polyamide alone, and thus the crystallinity is low and the adhesive strength is also lowered. In addition, when the ionomer resin is more than 30% by weight, since the properties of the hot melt adhesive are controlled by the ionomer resin, crystallinity is drastically reduced, so that the adhesive strength is lowered and the manufacturing cost is increased. Therefore, 5-30% by weight of the ionomer resin is considered to be the optimal condition.

This ionic copolymer neutralizes at least 10% of the carboxylic acid groups with metal ions. The metal cations constituting the ionic copolymer used in the present invention include monovalent, divalent and trivalent metals and belong to the group 1, 2, 3, 4 and 8 of the periodic table. Monovalent cations include natrium, potassium, lysine, cesium, silver, mercury, and copper cations. Divalent cations are beryllium, magnesium, calcium, strontium, barium, copper, cadmium, mercury, tin, lead, iron, cobalt, nickel and zinc ions.

Trivalent cations include aluminum, scandinium, and iron cations. The metal cations of the ionic copolymers best suited for the purpose of the composition of this invention are zinc and sodium cations. The degree of neutralization of the ionic copolymer by the metal cation should be at least 10% of the carboxyl group. It is generally stated that at least 50% of the acid groups should be neutralized. The degree of neutralization can be measured by well known techniques such as infrared spectroscopy or titration.

As the amount of ionomer resin used in the present invention increases, flexibility and impact resistance increase and adhesion improves.

Since the ionomer is rubbery, the Tg is low and the adhesion is good, thereby improving the adhesion. In addition, since the neutralized metal salt of the ionomer is present, it is well compatible with the polyamide component and does not cause phase separation. Therefore, the copolymerized polyamide produced has a low number of amides, so it has low crystallinity, excellent water resistance and low adhesive strength, and prevents degradation.In other words, the low amide group and low water absorption provide excellent resistance and do not lose elasticity and adhesive strength even at low temperatures. .

As described above, the adhesive conditions of the adhesive prepared according to the present invention are preferably carried out at a temperature above the melting temperature of the copolymerized polyamide, for example, at 90-250 ° C., in particular, the copolymerized polyamide is dissolved in a solvent such as methanol to form an adhesive. It is also possible to use.

On the other hand, the adhesive made of polyamide alone from which the ionomer resin other than the composition according to the present invention has been removed is not good because the adhesive strength is lowered, especially at low temperatures, the adhesiveness is lowered and the water resistance is lowered.

Since the polyamide 6/66/12 copolymer and the rubber ionomer resin are alloyed, the Tg is lower, the elasticity and flexibility are excellent, the water resistance is strong, and the adhesion is superior to that of the polyamide copolymer alone. In addition, there are many excellent properties such as not falling off the adhesive strength at low temperature, it is not limited to the use such as wick, woven fabric, nonwoven fabric, metal bonding, elastic sealant.

Hereinafter, the present invention will be described in detail with reference to Examples.

The amino mirine used in this invention is a product of Dupont.

The content was 5-30% by weight as sulfine 8020,8528,8920,9020,9520,9721. The ionomer copolymer is a zinc or shodoop cheant of the ethylene-methacrylic acid copolymer and the simple physical properties are shown in Table 1.

Melt index means g / 10 min.

TABLE 1

Example 1-6

Adjusting the monomer composition of caprolactam, hexamethylene, diamine, adipate and aminododecanoic acid as shown in Table 2, while adjusting 5-10% by weight of water, adding this to a 1kg autoclave and replacing with nitrogen gas, The temperature is raised to 280 ° C. for 2 hours at 15 kg / cm ³ . It was maintained at 280 ° C. under pressure for 3 hours, and then pressurized for 1 hour at atmospheric pressure and then maintained for 3 hours. The obtained copolymerized polyamide polymer was cut to a thickness of about 1 mm, dried, and the melting point was measured by a hot plate melting point meter (see Table 1).

Relative viscosity in Table 2 is the value measured at 25 ° C. for 1 g / 10 cm 1 of 98% sulfuric acid.

TABLE 2

Example 7

90 wt% of the copolymerized polyamide obtained in Example 4 and 10 wt% of Sullin 9020 were blended and alloyed with a twin screw compounder. The compounding condition is that the barrel temperature is pelletized by passing through a zone 1: 200 ℃, zone 2: 190 ℃, zone 3: 180 ℃, zone 4: 180 ℃, zone 5: 200 ℃, and 250 RPM cooling water tank. To prepare. At this time, the cooling water temperature should be maintained at 5-6 ℃. The obtained copolymerized polyamide polymer was cut to a thickness of about 1 mm and dried, and then the melting point was measured by a hot plate melting point meter. The relative viscosity was measured at 25 ° C of a 1g / 100ml solution of 98% sulfuric acid, and the melting point was 105-115 ° C and the viscosity was 2.15.

Example 8

85% by weight of the copolymerized polyamide obtained in Example 5 and 15% by weight of sulfine 8020 were blended to prepare the same method as in Example 7. Melting | fusing point of the obtained copolymerized polyamide was 120-125 degreeC, and the viscosity was 2.20.

Example 9

80% by weight of the copolymerized polyamide obtained in Example 3 and 20% by weight of sulfine 9520 were blended to prepare the same conditions as in Example 7. Melting | fusing point of the obtained copolymerized polyamide was 135-140 degreeC, and the viscosity was 2.08.

Example 10-15

80% by weight of the copolymerized polyamide obtained in Example 2 and 20% by weight of DuPont sulfin ionomer resin were blended by grade (8020,8528,8920,9020,9520,9721), respectively, in the same manner as in Example 7. Amide was prepared. The obtained copolymerized polyamide was dissolved in a solvent in which methanol and methylchloroform were mixed in a weight ratio of 1: 1, and coated on a release paper at a knife corner to prepare a film having a thickness of 60 u.

The film is sandwiched between cotton float 100 cotton shirting and bonded at a temperature of -15 ° C above the melting point for 10 seconds (1 second for steam) with a compression time of 0.3 kg / cm ² . Initial adhesive strength for the bonded adhesive strength after washing and dry strength at low temperature (-40 ℃) after dry cleaning was measured and the results are shown in Table 3.

Here, the adhesive strength after washing was measured by immersing the bonded product in an aqueous solution of 0.5% of high tie, rotating for 5 minutes, drying at an temperature of 65 ± 5 ° C. for 1 hour, and repeating five times. Bonded to a mixed solution of 100 ml perchlorethylene 100 ml dodecylbenzene, 1 g of sodium sulfonic acid, 1 g of polyoxyethylene phenyl ether, and 1 g of pure water, rotated for 5 minutes, dried at 65 ± 5 ° C for 30 minutes, and then repeated 5 times. It measures what was done. The adhesive strength at low temperature was measured at -40 ° C after 48 hours at -40 ° C.

TABLE 3

As can be seen from the above results, it can be seen that the copolymerized polyamide prepared by aligning the ionomer resin has improved adhesion, and in particular, washing resistance, chemical resistance, and low temperature adhesive strength.

[Example 16-21]

Copolymerized polyamide was prepared in the same manner as in Example 7, adjusting the monomer composition of the copolymerized polyamide obtained in Example 4 and DuPont acid sulfine 9020, as shown in Table 4. Bonding of the obtained copolymerized polyamide was carried out in the same manner as in Example 10-15. The results are shown in Table 4.

TABLE 4

As can be seen from the above results, as the ionomer content is increased, the adhesion is improved, but when it is more than 30% by weight, it is rather decreased.

As described above, the present invention, unlike the prior art, is prepared by preparing copolymerized polyamide using ε-caprolactam or ε-amino caproic acid amino dodecanoic acid or lauryl lactam, hexamethylene diamine and adipic acid as basic components. A hot melt adhesive made of copolymerized polyamide prepared by aligning ionomer resin with copolymerized polyamide. Copolymerized polyamide has a very high elasticity, is rich in flexibility, and has high water resistance. It has excellent properties such as good adhesion at low temperatures and low adhesion to alcohol-based solvents, and can be widely used for bonding metals such as wicks, woven fabrics, nonwoven fabrics, and sealants.

Claims (2)

Copolymer polyamide 70-95 weight of 20-65 weight% of epsilon caprolactam, 20-65 weight% of aminododecanoic acid, and 10-50 weight% of hexo methylenediamine adipate by heat-copolymerization at 200-300 degreeC in water presence. A method of producing a hot melt adhesive by blending 5-30% by weight of ionomer resin to a large amount at a barrel temperature of 180-200 ° C. and 180-250 RPM with a twin screw extruder. 2. Process according to claim 1, wherein ethylene-methacrylate zinc or sodium salt is neutralized with at least 10% of carboxylic acid groups with metal ions with ionomer resin.