WO2017088765A1

WO2017088765A1 - Method for preparing modified wet-cured polyurethane hot melt adhesive

Info

Publication number: WO2017088765A1
Application number: PCT/CN2016/106955
Authority: WO
Inventors: 曾作祥; 曹�盛; 李哲龙; 朱万育
Original assignee: 上海天洋热熔粘接材料股份有限公司; 华东理工大学; 昆山天洋热熔胶有限公司
Priority date: 2015-11-24
Filing date: 2016-11-23
Publication date: 2017-06-01
Also published as: CN105255434B; CN105255434A

Abstract

Disclosed in the present invention is a method for preparing a modified wet-cured polyurethane hot melt adhesive, relating to the technical field of polyurethane adhesive synthesis. The inventiveness of the present invention is characterised in terms of: using pentaerythritol diacrylate and modifying traditional wet-cured polyurethane hot melt adhesives; as said acrylate, containing two hydroxyl groups, can act as a chain extender, adjusting the amount of pentaerythritol diacrylate and controlling the viscosity of a target product within a reasonable range causes the target product to be advantageous for construction and to have a satisfactory initial adhesion; in addition, as the modifier contains short-chain functional group acrylates, the final stripping strength of the target product is also superior to traditional conventional products.

Description

Preparation method of modified moisture-curing polyurethane hot melt adhesive

Technical field

The invention discloses a preparation method of a modified moisture-curing polyurethane hot melt adhesive, and belongs to the technical field of polyurethane adhesive synthesis.

Background technique

The moisture-curing polyurethane adhesive is a reactive adhesive. The adhesive mechanism includes not only the adhesive force contributed by the intermolecular forces, but also the active hydrogen contained in the -NCO group reacting with the water diffused into the colloid. The amino group is then reacted with the -NCO group to produce a urea group, thereby forming a crosslinked structure to achieve adhesion to the substrate. The colloid after the bond curing not only fails to melt again, but also greatly enhances the bond strength of the glue due to the reactive component in the colloid reacting with the corresponding active component in the substrate.

With the improvement of people's living standards, the requirements and demands for clothing consumer goods are getting higher and higher, the fabric linings of various special functional materials are more and more composite, the materials and quality of various fabrics are different, and the types of adhesives required are needed. It is not the same as the sizing temperature. Chinese patent CN201310469047.8 discloses a preparation method of moisture-curing reactive polyurethane hot melt adhesive for textiles, but the initial adhesive strength and the final adhesive strength are relatively low, especially the initial tack force <1N/2.5 when the glue is applied for 10 minutes. Cm; Chinese patent CN201410691126.8 discloses a PTMG modified moisture-curing polyurethane hot melt adhesive (PUR) and a preparation method thereof, by adding a polytetrahydrofuran fan (PTMG) to PUR to increase the final adhesive strength of PUR, Reducing the viscosity of PUR, although the low viscosity PUR is easy to sizing, but the initial tack is still low, the initial tack at 10min when the sizing is 1.12N/2.5cm, which can not meet the initial tack and final bond strength. Specific application areas that are relatively demanding.

Summary of the invention

The object of the present invention is to solve the above problems and provide a method for preparing a modified moisture-curing polyurethane hot melt adhesive, so that the moisture-curing polyurethane hot melt adhesive prepared by the invention has high initial tack force and has higher Good final bond strength.

The technical scheme adopted by the invention is: a preparation method of a modified moisture-curing polyurethane hot melt adhesive, comprising the following steps:

(1) Adding polyester polyol, polyether polyol and auxiliary into a three-necked flask and stirring, heating to 120-130 ° C during stirring, and dehydrating at a constant pressure of 80-150 Pa for 2.0 h, then cooling to 90 ° C, nitrogen to atmospheric pressure;

(2) Under the protection of nitrogen, MDI and catalyst were added to the above reaction system, and reacted at 90-100 ° C, absolute pressure 80-100 Pa for 45 min, then pentaerythritol diacrylate was added, and the pressure was 95-105 ° C, absolute pressure. The reaction was carried out at 80-100 Pa for 1.0 h to obtain a prepolymer;

(3) The prepolymer obtained in the step (2) was transferred to an aluminum foil bag, and after sealing, it was aged at 85 ° C for 6 hours to obtain a target product.

In the above step (1), the polyether polyol is a mixture of two polyoxypropylene diols having a number average molecular weight of 1000 and 4000, and the two polyoxypropylene diols are hereinafter referred to as polyether 1000 and polyether 4000, respectively; The ester polyol is a polyhexamethylene adipate diol having a number average molecular weight of 3,000.

In the above step (1), the auxiliary agent includes a catalyst, a tackifier, and an antioxidant. Among them, the catalyst is stannous octoate; the tackifier is a terpene resin; and the antioxidant is named CHINOOX1010.

In the above step (2), the MDI is diphenylmethane diisocyanate selected from one of 4,4'-MDI, 2,4'-MDI and 2,2'-MDI.

Based on 1.0 mol of polyether 1000, the molar ratio of other reactants is: 0.1-0.2 mol of polyether 4000; 0.2-0.4 mol of polyhexamethylene adipate diol; 2.7-3.65 mol MDI; 0.35-0.50 Mol pentaerythritol diacrylate.

The amount of each additive added is a percentage of the total mass of the target product, which is 0.1% of the catalyst. The tackifier is 18-25% and the antioxidant is 0.50%.

The innovation of the invention: the modification of the traditional moisture-curing polyurethane hot melt adhesive by using pentaerythritol diacrylate, since the acrylate containing two hydroxyl groups can act as a chain extender, the dosage of pentaerythritol diacrylate can be adjusted. The viscosity of the target product is controlled within a reasonable range, so that it is easy to construct and has a satisfactory initial tack force, and at the same time, since the modifier contains a short-chain functional group acrylate, the target product is finally peeled off. For traditional products.

Detailed ways

The present invention is further described by the following examples, but is not limited thereto.

Example 1

Weigh polyether 1000 (100g), polyether 4000 (72g), polyhexane adipate diol (96g), terpene resin (80.1g), antioxidant CHINOX1010 (2.22g), add three-necked flask Stir in the mixture, heat to 120-130 ° C during the stirring process, and dehydrate at a constant pressure of 80-150 Pa for 2.0 h, then cool to 90 ° C, pass nitrogen to normal pressure; add 4,4′- under nitrogen protection MDI (85.65g), catalyst stannous octoate (0.44g), then reacted at 90-100 ° C, absolute pressure 80-100Pa for 45min, and then added pentaerythritol diacrylate (8.54g) under nitrogen and atmospheric pressure and nitrogen protection. ), reacting at 95-105 ° C, absolute pressure 80-100 Pa for 1.0 h, to obtain a prepolymer;

The above prepolymer was discharged under a nitrogen atmosphere and sealed in a package, and aged in an environment of 85 ° C for 6 hours. The resulting sample number is P1.

Example 2

Weigh polyether 1000 (100g), polyether 4000 (40g), polyhexane adipate diol (69g), terpene resin (86.95g), antioxidant CHINOX1010 (1.89g), add three-necked flask Stir in the mixture, heat to 120-130 ° C during the stirring process, and dehydrate at a constant pressure of 80-150 Pa for 2.0 h, then cool to 90 ° C, pass nitrogen to normal pressure; add 2,4′- under nitrogen protection MDI (67.63g), Catalyst stannous octoate (0.38g), then reacted at 90-100 ° C, absolute pressure 80-100Pa for 45min, then added pentaerythritol diacrylate (12.2g) under nitrogen and atmospheric pressure, under the protection of nitrogen, at 95-105 The reaction was carried out for 1.0 h at an absolute pressure of 80-100 Pa to obtain a prepolymer;

The above prepolymer was discharged under a nitrogen atmosphere and sealed in a package, and aged in an environment of 85 ° C for 6 hours. The resulting sample number is P2.

Example 3

Weigh polyether 1000 (100g), polyether 4000 (80g), polyhexane adipate diol (60g), terpene resin (113.1g), antioxidant CHINOX1010 (2.26g), add three-necked flask Stir in the mixture, heat to 120-130 ° C during the stirring process, and dehydrate at a constant pressure of 80-150 Pa for 2.0 h, then cool to 90 ° C, pass nitrogen to normal pressure; add 2, 2 '- under nitrogen protection MDI (86.94g), catalyst stannous octoate (0.45g), then reacted at 90-100 ° C, absolute pressure 80-100Pa for 45min, then added pentaerythritol diacrylate (9.76g) under nitrogen and atmospheric pressure and nitrogen protection. ), reacting at 95-105 ° C, absolute pressure 80-100 Pa for 1.0 h, to obtain a prepolymer;

The above prepolymer was discharged under a nitrogen atmosphere and sealed in a package, and aged in an environment of 85 ° C for 6 hours. The resulting sample number is P3.

Example 4

Weigh polyether 1000 (100g), polyether 4000 (40g), polyhexane adipate diol (120g), terpene resin (102.35g), antioxidant CHINOX1010 (2.22g), add three-necked flask Stir in the mixture, heat to 120-130 ° C during the stirring process, and dehydrate at a constant pressure of 80-150 Pa for 2.0 h, then cool to 90 ° C, pass nitrogen to normal pressure; add 4,4′- under nitrogen protection MDI (90.34g), catalyst stannous octoate (0.27g), then reacted at 90-100 ° C, absolute pressure 80-100Pa for 45min, then added pentaerythritol diacrylate (9.76g) under nitrogen and atmospheric pressure and nitrogen protection. ), reacting at 95-105 ° C, absolute pressure 80-100 Pa for 1.0 h, to obtain a prepolymer;

The above prepolymer was discharged under a nitrogen atmosphere and sealed in a package, and aged in an environment of 85 ° C for 6 hours. The resulting sample number is P4.

test sample

The Brookfield viscometer was used to test the viscosity of samples P0~P4 and similar commercial products, and the temperature was controlled at 100 °C and 120 °C, respectively;

The peel strength test of the above samples and commercially available conventional products is based on the standard FZ/T01085-2009, the adherend used is polyester cotton 6535, and the sizing temperature is 100 ° C;

The peel strength of the bonded samples was measured for 10 min and 48 h, respectively, and the stripping strength of 10 min was defined as the initial stripping strength (or initial tack strength), and the stripping strength of 48 h was the final stripping strength; Table 1 below.

Table 1 Melt viscosity, initial adhesion strength and final peel strength of each sample

It can be clearly seen from the above Table 1 that the wet-cured polyurethane hot melt adhesive prepared by the present invention has a relatively high peeling strength after 10 minutes of sizing in the case where the amount of sizing is relatively flat compared with the commercially available conventional similar products. Higher, the peel strength after sizing for 48h is also significantly higher, that is, the moisture-curing polyurethane hot melt adhesive prepared by the invention has good initial tack and high final adhesive strength.

Claims

A preparation method of a modified moisture-curing polyurethane hot melt adhesive, characterized in that the method comprises the following steps:

(1) Adding polyester polyol, polyether polyol and auxiliary into a three-necked flask and stirring, heating to 120-130 ° C during stirring, and dehydrating at a constant pressure of 80-150 Pa for 2.0 h, then cooling to 90 ° C, nitrogen to atmospheric pressure;

(2) Under the protection of nitrogen, MDI and catalyst were added to the above reaction system, and reacted at 90-100 ° C, absolute pressure 80-100 Pa for 45 min, then pentaerythritol diacrylate was added, and the pressure was 95-105 ° C, absolute pressure. The reaction was carried out at 80-100 Pa for 1.0 h to obtain a prepolymer;

(3) transferring the prepolymer obtained in the step (2) into an aluminum foil bag, and after curing, aging at 85 ° C for 6 hours to obtain a target product;

The polyether polyol is a mixture of two polyoxypropylene diols having a number average molecular weight of 1000 and 4000, respectively; the polyester polyol is a polyhexane adipate diol having a number average molecular weight of 3000;

Based on 1.0 mol of the polyoxypropylene diol having a number average molecular weight of 1000, the molar ratio of the other reactants is 0.1-0.2 mol of polyoxypropylene diol having a number average molecular weight of 4000; 0.2-0.4 mol of polyadipate hexane. Alcohol ester diol; 2.7-3.65 mol MDI; 0.35-0.50 mol pentaerythritol diacrylate.
The method for preparing a modified moisture-curing polyurethane hot melt adhesive according to claim 1, wherein the auxiliary agent comprises a catalyst, a tackifier and an antioxidant; wherein the catalyst is stannous octoate and the tackifier is ruthenium. The olefin resin, the antioxidant is tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] pentaerythritol ester.
The method for preparing a modified moisture-curing polyurethane hot melt adhesive according to claim 2, wherein the additive is added in a percentage of the total mass of the target product, respectively: 0.1% of the catalyst, and the tackifier 18 -25%, antioxidant 0.50%.
The method for preparing a modified moisture-curing polyurethane hot melt adhesive according to claim 1, wherein the MDI is diphenylmethane diisocyanate selected from the group consisting of 4,4'-MDI, 2,4'-MDI and One of 2, 2'-MDI.