CN113637397B

CN113637397B - Water-based surface treating agent, high-flexibility skin-feel PVC leather and preparation method

Info

Publication number: CN113637397B
Application number: CN202110994460.0A
Authority: CN
Inventors: 匡建武; 张术根; 张金晖; 唐炯珲
Original assignee: Beston Decorative Products Suzhou Co ltd
Current assignee: Beston Decorative Products Suzhou Co ltd
Priority date: 2021-08-27
Filing date: 2021-08-27
Publication date: 2022-02-22
Anticipated expiration: 2041-08-27
Also published as: CN113637397A

Abstract

The invention relates to a water-based surface treatment agent, high-flexibility skin-feel PVC leather and a preparation method thereof. The invention creatively adopts the reactive POSS in the aqueous surface treating agent, which not only can be uniformly dispersed in a system, but also can form a uniform and stable dispersion system together with the polysiloxane and the polymer resin, and simultaneously, the reactive POSS, the polysiloxane, the polymer resin and the cross-linking agent are matched for use, so that the viscoelastic coefficient of a coating formed by curing the finally prepared aqueous surface treating agent is close to that of human skin, flexible and pleasant touch can be given under the action of contact stress, and the wear resistance, chemical resistance and the like of the coating can be kept. The PVC leather is used for PVC leather, the plastic feeling of the traditional PVC surface treatment is effectively reduced, the high skin feeling acceptance of consumers is obtained, and meanwhile, the PVC leather has excellent wear resistance, chemical resistance and the like.

Description

Water-based surface treating agent, high-flexibility skin-feel PVC leather and preparation method

Technical Field

The invention belongs to the technical field of synthetic leather surface treatment, and particularly relates to a water-based surface treatment agent, high-flexibility skin-feel PVC leather and a preparation method thereof.

Background

The touch sense is a general term of mechanical stimulation such as human body contact, sliding, pressure sense and the like, exists based on skin sense, and has wider sensory experience compared with other organs with targeted sensory perception.

With the development of the industry, the requirements of terminal customers on automotive interior are higher and higher, and the comfort level is improved on the basis of meeting the physical property test standard, so that the surface touch feeling is required to be natural.

Currently, seat leather materials are in a large proportion in automobile interior trims, and tend to increase in recent years. The seat leather material is frequently contacted with the human body, so the requirements on the comfortable touch feeling and the environmental protection are higher. Most of the early high-grade vehicle interior decorations are coated by natural leather and are real leather interior decorations. But due to the high price, the resources are limited, and the production process of the dermis is not environment-friendly. PVC has the defects of bright appearance, wear resistance, folding resistance, acid and alkali resistance and the like, but has obvious soft touch.

In the prior art, methods for improving the touch feeling of the PVC surface are also available, such as introducing a siloxane substance with polyether modification into the surface treatment agent of the PVC artificial leather to improve the hand feeling of the PVC artificial leather. For example, the Chinese patent CN106349914A discloses an aqueous matte finishing agent for PVC leather and a preparation method thereof, wherein the finishing agent comprises the following components: the water-based polyurethane paint comprises water, silicon dioxide matting powder, polysiloxane water dispersion, water-based wax emulsion, a water-based wetting agent, a water-based defoaming agent and a thickening agent. Wherein the polysiloxane aqueous dispersion is polyether emulsified polysiloxane aqueous dispersion with the molecular weight of 2-110 ten thousand. However, the PVC artificial leather added with the polyether modified siloxane material still has a certain difference with the genuine leather in hand feeling, and cannot meet the increasingly severe requirements of end customers.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide an aqueous surface treating agent for endowing leather with high soft touch feeling.

The second purpose of the invention is to provide PVC leather with high flexible skin feel and a preparation method thereof.

In order to achieve the purpose, the invention adopts the technical scheme that:

the water-based surface treating agent comprises the following raw materials in parts by weight:

in the invention, the POSS: the british name polymeric silsesquioxane, cage polysilsesquioxane, is an inorganic core consisting of a siloxane backbone with alternating Si — O linkages, with grafting or polymerization reactions taking place between the polymer through reactive groups.

According to some embodiments of the invention, the reactive groups in the reactive POSS are selected from epoxy and/or hydroxyl groups.

According to some embodiments of the invention, the reactive POSS has the general structural formula (RSiO)_3/2)_nWherein n is 8-12, and n R substituents at least contain hydroxyl and terminal epoxy.

Preferably, the substituent containing the terminal epoxy group is selected from

In some preferred and specific embodiments, the reactive POSS has the formula:

wherein, one part of the 12R substituents is hydroxyl, and the other part of the substituents is selected from

Preferably, the molar ratio of the raw materials providing the hydroxyl and terminal epoxy substituents in the preparation of the reactive POSS is 1: 1. Such as SS-1396 from Quaker Color, Inc.

Due to the unique cage-shaped framework structure of the reactive POSS, the viscoelastic coefficient gamma 0.8 of the coating is close to the human skin, and the reactive POSS can give flexible and pleasant touch under the stress action of touch pressure.

According to some embodiments of the invention, the polymer of the waterborne polymer resin contains a carboxyl and IPN interpenetrating network structure resin. The aqueous polymer resin is polycarbonate-polyether polyurethane aqueous dispersion liquid.

The touch feeling is related to the long chain segment structure and the short chain segment structure of the polymer in the waterborne polymer resin, the long chain segment is a flexible chain segment, the short chain segment is a rigid chain segment, and when the waterborne polymer resin is selected, the resin with balanced physical properties and touch feeling is selected to be matched under the condition that the requirements of the whole automobile or the whole machine production enterprise on various indexes such as wear resistance, deflection, aging and the like are met. The selected water-based polymer resin and the cross-linking agent are subjected to cross-linking reaction in the drying process, and the reactive POSS also participates in the cross-linking reaction to form a stable and continuous compact coating, so that the main chain physical strength of the film-forming resin is maintained, and the side chain flexible touch feeling is realized.

The solid content of the waterborne polymer resin is 30-45%, such as 35%.

According to some embodiments of the invention, the cross-linking agent is a polycarbodiimide-based cross-linking agent.

According to some embodiments of the invention, the polysiloxane has an average particle size of 1 to 10 μm. Preferably, the average particle diameter is 2 to 5 μm. The average particle diameter is specifically 3 μm. The polysiloxane acts as a feel improver to reduce the plastic feel of the polymer.

The second technical scheme adopted by the invention is as follows: a PVC leather comprises a PVC surface and a surface treatment layer formed on the PVC surface, wherein the surface treatment layer is of a single-layer or multi-layer structure, and when the surface treatment layer is of a single-layer structure, the surface treatment agent used by the surface treatment layer is the aqueous surface treatment agent; when the surface treatment layer has a multilayer structure, the surface treatment agent used for the outermost layer of the surface treatment layer is the aqueous surface treatment agent described above.

Preferably, the surface treatment layer is a multilayer structure, and comprises a first surface treatment layer formed on the PVC skin and a second surface treatment layer formed on the first surface treatment layer, wherein the surface treatment agent adopted by the second surface treatment layer is the aqueous surface treatment agent.

Further preferably, the surface treatment agent used in the first surface treatment layer is a conventional commercially available aqueous polyurethane surface treatment agent. Such as Quaker MT-2115.

The third technical scheme adopted by the invention is as follows: the preparation method of the PVC leather comprises the steps of coating the water-based surface treatment agent on a PVC surface, drying to form the surface treatment layer, and embossing by using an engraving die with a bionic structure.

Further, the bionic structure is provided with a convex bending part formed on the carving mould.

The traditional embossing mold is mainly characterized in that pre-designed textures are carved on the mold, and the textures are vertically carved with different depths on a plain mold, so that a texture effect is embodied, and the carved mold texture effect is shown in fig. 1.

The carving mould with the bionic structure is used for carving directions at different angles on the basis of traditional laser carving, and finally carving curved textures, namely the textures have bending angles, so that the carved mould has the texture effect, as shown in figure 2. After the carving mould with the bionic structure is used for embossing, the surface texture on the leather also has a bending angle, diffuse reflection is generated to light, the glossiness is low, and the texture is fine and smooth. The carving mould of the bionic structure can be purchased from other places.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

the invention creatively adopts the reactive POSS in the aqueous surface treating agent, which not only can be uniformly dispersed in a system, but also can form a uniform and stable dispersion system together with the polysiloxane and the polymer resin, and simultaneously, the reactive POSS, the polysiloxane, the polymer resin and the cross-linking agent are matched for use, so that the viscoelastic coefficient of a coating formed by curing the finally prepared aqueous surface treating agent is close to that of human skin, flexible and pleasant touch can be given under the action of contact stress, and the wear resistance, chemical resistance and the like of the coating can be kept. The PVC leather is used for PVC leather, the plastic feeling of the traditional PVC surface treatment is effectively reduced, the high skin feeling acceptance of consumers is obtained, and meanwhile, the PVC leather has excellent wear resistance, chemical resistance and the like.

Drawings

FIG. 1 is a diagram illustrating the texture effect of a conventional engraving mold;

FIG. 2 is a diagram of the effect of a typical texture of an engraving mold having a bionic structure according to the present invention;

FIG. 3 is a 5000-magnification SEM image of a reactive POSS as employed in example 1 of the present invention;

fig. 4 is an SEM image (4 times effect) of the engraving mold having a bionic structure employed in example 1 of the present invention;

fig. 5 is an SEM image (50 times effect) of the engraving mold having a bionic structure employed in example 1 of the present invention;

fig. 6 is an SEM image (100 times effect) of an engraving mold having a bionic structure employed in example 1 of the present invention;

FIG. 7 is an SEM image of the surface of PVC leather of example 1 of the present invention at 200 magnifications;

FIG. 8 is a 1000-magnification SEM image of the surface of PVC leather according to example 1 of the present invention;

FIG. 9 is a screenshot of the recording instrument during the noise reduction test of the PVC leather of example 1 of the present invention;

fig. 10 is a screenshot of the recording instrument during noise reduction testing for a commercial PVC leather.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications may be made by those skilled in the art after reading the disclosure of the present invention, and such equivalents may fall within the scope of the invention as defined by the appended claims.

The structural formula of the reactive POSS employed in the following examples is as follows:

wherein the 12R substituents are

And hydroxyl groups, the molar ratio of the raw materials providing the two substituents being 1: 1. The SEM image of the material is shown in FIG. 3.

Example 1

The PVC leather for the vehicle is prepared by the following method:

(1) preparation of aqueous surface treating agent

50g of reaction type POSS, 850g of waterborne polymer resin (specifically MT 1618 and purchased from Quaker Color), 50g of polysiloxane (specifically AW 858 and purchased from Quaker Color) and 50g of polycarbodiimide crosslinking agent (such as model AM 2532XL) are stirred and mixed uniformly to prepare the waterborne surface treating agent.

(2) Preparation of PVC leather

Coating a conventional waterborne polyurethane surface treatment agent on the plain weave type PVC surface, drying to form a first surface treatment layer, coating the waterborne surface treatment agent prepared in the step (1) on the first surface treatment layer, drying at 125 +/-10 ℃ to form a second surface treatment layer, and then embossing by adopting an engraving mold with a bionic structure to obtain the PVC leather.

In this example, the engraving mold having a bionic structure was purchased, and SEM images of the surface thereof are shown in fig. 4 to 6.

SEM test is carried out on the surface of the PVC leather, and the results are shown in figure 7(200 multiplying power) and figure 8(1000 multiplying power), and it can be seen from the figures that the surface treatment layer presents a mellow and smooth submicroscopic structure at a high multiplying power, and the plastic feeling of the surface of the traditional PVC leather is effectively reduced.

Noise reduction test

The leather of example 1 and the commercially available PVC leather were subjected to a noise resistance test according to the German automotive industry Standard VDA 230-206.

Two sheets, sheet A and sheet B, were cut from the leather and sheet A was secured to the apparatus described in section 3 of VDA230-206 as a fastening tab. The sheet B is mounted on the moving head of the instrument. The sheet B is pressed against the sheet a, and the moving head is operated to move the sheet B on the sheet a. The pressing force of the sheet B against the sheet a was adjusted so that the pressing forces were 10N and 40N, respectively. For each adjusted pressure, the speed at which sheet B was moved over sheet A was adjusted, and noise tests were conducted at speeds of 1mm/s and 4mm/s, respectively. For each test, the RPN value output by the instrument was recorded. The lower the RPN value, the better the noise resistance.

Table 1 shows the results of the noise test of the PVC leather of example 1

FIG. 9 also shows an interface screenshot of the recording instrument of the leather of example 1 during the noise reduction test; fig. 10 shows an interface screenshot of a recording instrument during a noise reduction test for a commercial PVC leather.

The noise reduction data are graded by 1-9, the grade 1-3 (green grade) is a low noise surface, the grade more than 5 (red grade) is a noise surface, and the higher the numerical value is, the higher the noise is.

As can be seen from fig. 9 and 10, the noise reduction data of example 1 is level 1 (green rating), low noise surface. The noise reduction data for the commercial PVC leather was 7 (red rating) and abnormal noise was produced when rubbed.

And the coefficient of kinetic friction of the PVC leather of the example 1 is 0.1373, which is far lower than the coefficient of kinetic friction of 0.4639 of the commercial PVC leather. The pulse value of the PVC leather of example 1 during the test was 0, which is much lower than the pulse value 642 of the commercial PVC leather. From a user experience perspective, the product of embodiment 1 can provide significant noise reduction.

The PVC leather of example 1 was also tested for viscoelastic coefficient, touch, abrasion resistance, light resistance, and heat resistance, and the results are shown in table 2.

Table 2 shows the results of the physical property test of the PVC leather of example 1

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

Claims

1. An aqueous surface treatment agent characterized by: the water-based surface treatment agent comprises the following raw materials in parts by weight:

80-85 parts of water-based polymer resin;

5-10 parts of reactive POSS;

5-10 parts of polysiloxane;

3-7 parts of a crosslinking agent;

the aqueous polymer resin is polycarbonate-polyether polyurethane aqueous dispersion;

the structural formula of the reactive POSS is as follows:

，

、

；

The cross-linking agent is a polycarbodiimide cross-linking agent.

2. The aqueous surface treating agent according to claim 1, characterized in that: the average particle size of the polysiloxane is 1-10 mu m.

3. The PVC leather comprises a PVC surface and a surface treatment layer formed on the PVC surface, wherein the surface treatment layer is of a single-layer or multi-layer structure, and is characterized in that: when the surface treatment layer has a single-layer structure, the surface treatment agent used for the surface treatment layer is the aqueous surface treatment agent according to claim 1 or 2; when the surface treatment layer has a multilayer structure, the surface treatment agent used for the outermost layer of the surface treatment layer is the aqueous surface treatment agent according to claim 1 or 2.

4. The PVC leather of claim 3, wherein: the surface treatment layer comprises a first surface treatment layer formed on the PVC surface and a second surface treatment layer formed on the first surface treatment layer, and the surface treatment agent adopted by the second surface treatment layer is the aqueous surface treatment agent.

5. A method for preparing PVC leather according to claim 3, characterized in that: the preparation method comprises the steps of coating a surface treating agent on the PVC surface, drying to form a surface treating layer, and embossing by using an engraving mold with a bionic structure.