White-skin composite resin composition and preparation method thereof

Abstract

The invention belongs to the field of leather coating, and particularly relates to a white-skin composite resin composition and a preparation method thereof. The white skin composite resin composition is prepared from the following raw materials: DOWELLIU RU2301, DOWELLIU RU2307, DOWELLIIC RA1300, DOWELLIIC RA1107, an amine neutralizing agent, a thickening agent, a light stabilizer, water and the like. The white leather composite resin composition can endow leather with soft, comfortable and smooth hand feeling, and is weak in load and good in fitting degree with crust leather; when being used for white leather coating, the white leather coating has very strong covering power, the spraying frequency can be reduced by more than two times, the production efficiency can be effectively improved, the production cost can be reduced, and meanwhile, white paste and water can be simply added for use, so that the use of customers is greatly facilitated; in addition, excellent yellowing resistance and aging resistance are achieved, and the durability of whiteness is effectively guaranteed.

Description

Technical Field

[0001] The invention belongs to the field of genuine leather finishing, and particularly relates to a white leather composite resin composition and a preparation method thereof. Background Art

[0002] Leather finishing is an extremely important process in the leather preparation process. It is usually achieved by adding different film-forming substances and additives to obtain excellent physical properties, so as to meet the product's use requirements. Among them, white, as a classic color, occupies a large proportion in leather finishing.

[0003] Traditional leather finishing involves preparing film-forming substances and additives on the spot, which is complex to operate and results in poor stability of the prepared slurry. In addition, the slurry formula requires repeated testing by finishing engineers, which is time-consuming and laborious.

[0004] The key technical difficulty in making white leather is how to maintain the durability of whiteness. For white leather, it is usually required to be pure white, without obvious green light, blue light, darkening, etc., and at the same time have excellent resistance to sunlight, ultraviolet rays, high temperature, humidity and heat.

[0005] It is usually difficult to meet the above-mentioned multiple performance requirements by simply selecting and combining film-forming resins and additives. In addition, in order to improve the whiteness of the finished leather, the amount of white pigment slurry is usually increased during the leather making process to achieve the covering effect of the finishing layer. Moreover, the number of spraying times and the thickness of the coating are high, which results in a decrease in finishing efficiency and an increase in leather making costs.

[0006] Therefore, based on this, the technical solution of the present invention is proposed. Summary of the invention

[0007] In order to solve the problems existing in the prior art, the present invention aims to provide a white leather composite resin composition and a preparation method thereof. The product is used for white leather finishing and has the performance characteristics of strong hiding power, weak load, good fit, excellent light resistance, heat resistance and aging resistance, etc. It has a significant whitening effect, can effectively reduce the number of spraying times, improve production efficiency and reduce production costs.

[0008] The invention provides a white skin composite resin composition, which comprises the following raw materials in parts by weight: 15 to 20 parts of DOWELLIU RU2301, 20 to 25 parts of DOWELLIU RU2307, 10 to 15 parts of DOWELLIC RA1300, 5 to 10 parts of DOWELLIC RA1107, 4 to 8 parts of DOWELLIU PU20205, 3 to 6 parts of DOWELLER FILLER 4683, 3 to 6 parts of DOWELLER WAX 5050, 0.5 to 1.5 parts of an amine neutralizer, 1 to 2 parts of a thickener, 0.1 to 0.2 parts of a light stabilizer, and 20 to 25 parts of water.

[0009] To facilitate understanding of the present invention, some of the raw materials in the present invention are described:

[0010] The DOWELLIU RU2301 is a medium-soft aliphatic polyurethane resin produced by Sichuan Dawei Technology Co., Ltd. The resin has good embossing cut resistance, drop resistance, and abrasion resistance, and has excellent yellowing resistance and bending resistance. Its physical and chemical data are shown in Table 1.

[0011] Table 1

[0012] Physical and chemical data indicators data Solid content (%) 40±1 <![CDATA[Tensile set strength (N / mm 2 )]]> 3～3.5 Resistance to light yellowing (80℃, 24h) ≥4.5 Heat-resistant yellowing (120℃, 4h) ≥4.5 Wear resistance ≥500 times Normal temperature bending (25℃) ≥100,000 times Low temperature bending (-15℃) ≥60,000 times

[0013] The DOWELLIU RU2307 is a medium-soft aliphatic polyurethane resin produced by Sichuan Dawei Technology Co., Ltd. The resin has good leveling properties, a comfortable and natural coating, and no load feeling. It also has excellent water resistance and solvent resistance. Its physical and chemical data are shown in Table 2 below.

[0014] Table 2

[0015] Physical and chemical data indicators data Solid content (%) 35±1 <![CDATA[Tensile set strength (N / mm 2 )]]> 3.5～4 Resistance to light yellowing (80℃, 24h) ≥4.5 Heat-resistant yellowing (120℃, 4h) ≥4.5 Normal temperature bending (25℃) ≥100,000 times Low temperature bending (-15℃) ≥50,000 times Water absorption (weight method) % ≤5 Solvent resistance (butyl acetate, area method) % ≤200

[0016] The DOWELLIC RA1300 is a medium-soft acrylic resin produced by Sichuan Dawei Technology Co., Ltd. The resin has a tough and non-sticky film and has excellent cold-resistant and tortuosity performance. It also has high physical properties similar to polyurethane. Its physical and chemical data are shown in Table 3.

[0017] Table 3

[0018] Physical and chemical data indicators data Solid content (%) 35±1 <![CDATA[Tensile set strength (N / mm 2 )]]> 3.5～4 Resistance to light yellowing (80℃, 24h) ≥4.5 Heat-resistant yellowing (120℃, 4h) ≥4.5 Normal temperature bending (25℃) ≥30,000 times Low temperature bending (-15℃) ≥50,000 times

[0019] The DOWELLIC RA1107 is a soft acrylic resin produced by Sichuan Dawei Technology Co., Ltd. The resin is transparent, plump, non-sticky, and has good resilience. It can effectively improve the covering power of the coating without a sense of heavy coating. Its physical and chemical data are shown in Table 4.

[0020] Table 4

[0021] Physical and chemical data indicators data Solid content (%) 35±1 <![CDATA[Tensile set strength (N / mm 2 )]]> 1.5～2 Resistance to light yellowing (80℃, 24h) ≥4.5 Heat-resistant yellowing (120℃, 4h) ≥4.5 Elongation at break (%) ≥1200 <![CDATA[Tensile strength (N / mm 2 )]]> ≤4

[0022] The DOWELLIU PU20205 is an aliphatic polyurethane matting polymer produced by Sichuan Dawei Technology Co., Ltd. The polymer has an average particle size of 3 to 5 microns and has self-matting properties. By controlling the particle size, the expected matting effect can be achieved while avoiding the formation of a rough surface, which can improve the covering power, stain resistance and color retention of the coating. It can be used in the coating process to reduce the amount of white slurry used. Its physical and chemical data are shown in Table 5.

[0023] Table 5

[0024] Solid content (%) Average particle size (micrometers) Volume solid content (%) pH 32±1 3～5 55～60 8.5～10.5

[0025] The DOWELLER FILLER 4683 is a matting filler produced by Sichuan Dawei Technology Co., Ltd. The filler has a strong matting ability, can accelerate the drying speed of the coating, prevent the coating from being sticky, and increase the release property of the coating. The solid content of the filler is 23-25%.

[0026] The DOWELLER WAX 5050 is a paraffin water-based emulsion produced by Sichuan Dawei Technology Co., Ltd. The wax emulsion has a smooth and fine feel, can enhance the waxy feel of the coating, reduce the plastic feel of the coating, and does not affect the gloss and yellowing resistance of the coating. The solid content is 10-12%.

[0027] Preferably, the white skin composite resin composition comprises the following raw materials in parts by weight: 18 parts of DOWELLIURU2301, 23 parts of DOWELLIU RU2307, 12 parts of DOWELLIC RA1300, 7 parts of DOWELLIC RA1107, 7 parts of DOWELLIUPU20205, 3.5 parts of DOWELLER FILLER4683, 3.5 parts of DOWELLER WAX5050, 0.7 parts of amine neutralizer, 1.6 parts of thickener, 0.15 parts of light stabilizer, and 23.55 parts of water.

[0028] Preferably, the amine neutralizer is an organic amino compound, including but not limited to one or both of AMP-95 and DMAE, which are commercially available.

[0029] Preferably, the thickener is an aqueous thickener, including but not limited to one or both of ACRYSOL ASE-60 and ACRYSOL TT-935, which are commercially available.

[0030] Preferably, the light stabilizer is an ultraviolet light absorber or a hindered amine light stabilizer, including but not limited to one or a combination of two or more of Tinuvin 123DW, Tinuvin 9945DW, Tinuvin 479DW, Tinuvin 783FDL, Tinuvin 791FB, which are commercially available.

[0031] Based on the same technical concept, another embodiment of the present invention is to provide a method for preparing a white skin composite resin composition, the preparation method comprising the following steps:

[0032] (1) Under stirring conditions, DOWELLIU RU2301, DOWELLIU RU2307, DOWELLIC RA1300, DOWELLIC RA1107, DOWELLIU PU20205, DOWELLER FILLER 4683, DOWELLER WAX 5050, a light stabilizer and water are mixed to obtain a premix phase;

[0033] (2) After the premixed phase is uniformly defoamed, a thickener and an amine neutralizer are added and stirred. After completion, the mixture is filtered and packaged.

[0034] Preferably, in step (1), the stirring speed is 200-300 r / min, and the stirring temperature is 5-35°C.

[0035] Preferably, in step (2), the stirring time is 1 to 2 hours. After the stirring is completed, when the viscosity of the system meets the 4# Ford cup 25 to 35 seconds, it can be filtered through a 300-mesh filter and packaged.

[0036] The beneficial effects of the present invention are:

[0037] The white leather composite resin composition of the present invention can give the leather a soft, comfortable and smooth feel, has a weak load and good adhesion to the leather embryo; when used for white leather finishing, it has a strong hiding power, can reduce the number of spraying times by more than 2 times, can effectively improve production efficiency, and reduce production costs; at the same time, it can also be used by simply adding white slurry and water, which greatly facilitates the use of customers; and it also has excellent yellowing resistance and aging resistance, effectively ensuring the durability of whiteness. DETAILED DESCRIPTION

[0038] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0039] Example 1

[0040] This embodiment provides a method for preparing a white skin composite resin composition, the preparation method comprising:

[0041] Under the stirring state of 20 ℃ and 250r / min, 24.05g water, 16g DOWELLIU RU2301, 23g DOWELLIU RU2307, 13g DOWELLIC RA1300, 8g DOWELLIC RA1107, 5g DOWELLIUPU20205, 4.5g DOWELLER FILLER4683, 4.5g DOWELLER WAX5050 and 0.15g light stabilizer (Tinuvin123DW) were added in sequence, mixed evenly, stirred for 30 minutes and then allowed to stand for defoaming, 1.2g thickener (ACRYSOL ASE-60) and 0.6g amine neutralizer (AMP-95) were added, stirred for 1 hour, and after the stirring was completed, the system viscosity met the requirement of 4# Ford cup for 25 seconds, and then filtered through a 300-mesh filter for packaging.

[0042] Example 2

[0043] At 25°C and 300r / min stirring, add 23.55g water, 18g DOWELLIU RU2301, 23g DOWELLIU RU2307, 12g DOWELLIC RA1300, 7g DOWELLIC RA1107, 7g DOWELLIUPU20205, 3.5g DOWELLER FILLER4683, 3.5g DOWELLER WAX5050 and 0.15g light stabilizer (Tinuvin9945DW) in sequence, mix well, stir for 30 minutes and let stand to defoam, add 1.6g thickener (ACRYSOL TT-935) and 0.7g amine neutralizer (DMAE), stir for 2 hours, and after stirring, wait until the system viscosity meets 4# Ford cup 35 seconds, filter through a 300-mesh filter and package.

[0044] Example 3

[0045] Under the stirring state of 15 ℃ and 250r / min, 21.4g water, 19g DOWELLIU RU2301, 21g DOWELLIU RU2307, 14g DOWELLIC RA1300, 6g DOWELLIC RA1107, 7g DOWELLIUPU20205, 3.5g DOWELLER FILLER4683, 5.5g DOWELLER WAX5050 and 0.15g light stabilizer (Tinuvin479DW) were added in sequence, mixed evenly, stirred for 30 minutes and then allowed to stand for defoaming, 1.8g thickener (ACRYSOL ASE-60) and 0.65g amine neutralizer (AMP-95) were added, stirred for 1 hour, and after the stirring was completed, the system viscosity met the requirements of 4# Ford cup for 30 seconds, and then filtered through a 300-mesh filter for packaging.

[0046] Verification comparison

[0047] 1. Performance

[0048] The white skin composite resin compositions obtained in Example 1, Example 2 and Example 3 were tested, and their performance indicators all met the requirements of Table 6.

[0049] Table 6

[0050]

[0051]

[0052] Note:

[0053] Film forming conditions: dry film weight 3g, film forming dish diameter 9.5cm.

[0054] Film forming method: Place at room temperature until the surface is dry, then bake at 60℃ for 2-3h.

[0055] (II) Coating efficiency and cost

[0056] The composite resin composition is further compounded to obtain a coating slurry. The components and proportions of the coating slurry are shown in Table 7.

[0057] Table 7

[0058] Components Base slurry ratio water 350 H152 180 Composite resin 300 DowellicRA1260 120 DowellicRA1300 80 DowelliuRU2307 80 DowelliuNU2580 50 DowellerWax5057 80 DowellerFiller4683 50 SOFT4685 30 total 1320

[0059] Among them: there are two types of "composite resins" in Table 7. When the white skin composite resin composition obtained in Example 2 of the present invention is used, it is an "experimental example"; when a similar commercial product is used, it is a "comparative example".

[0060] The finishing process is: lightly spray the base slurry once, 1.6-1.8g / sf; brush the base slurry twice, 3g / sf, overnight, press the pores, 80 degrees, 150kg, 3S, vibrate to soften, spray 3-X, 1.6-1.8g / sf to cover.

[0061] The test results of the “experimental example” and the “comparative example” are shown in Table 8.

[0062] Table 8

[0063]

[0064] Note: The raw material cost saving of the experimental example is: (17.2-14) / 17.2*100%=18.6%.

[0065] From the comparison in the above table, when the same covering effect is achieved, the number of spraying times can be reduced by at least 2 times, which can save 18.6% of the raw material cost, while improving production efficiency and reducing energy consumption and labor costs.

[0066] (III) Comparison of whiteness durability

[0067] The comparison results of the “experimental example” and the “comparative example” are shown in Table 9.

[0068] Table 9

[0069]

[0070]

[0071] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A white skin composite resin composition, characterized in that The invention comprises the following raw materials in parts by weight: 15 to 20 parts of DOWELLIURU2301, 20 to 25 parts of DOWELLIU RU2307, 10 to 15 parts of DOWELLIC RA1300, 5 to 10 parts of DOWELLICRA1107, 4 to 8 parts of DOWELLIU PU20205, 3 to 6 parts of DOWELLER FILLER4683, 3 to 6 parts of DOWELLER WAX5050, 0.5 to 1.5 parts of amine neutralizer, 1 to 2 parts of thickener, 0.1 to 0.2 parts of light stabilizer and 20 to 25 parts of water.

2. The white skin composite resin composition according to claim 1, characterized in that The invention comprises the following raw materials in parts by weight: 18 parts of DOWELLIU RU2301, 23 parts of DOWELLIU RU2307, 12 parts of DOWELLIC RA1300, 7 parts of DOWELLIC RA1107, 7 parts of DOWELLIU PU20205, 3.5 parts of DOWELLER FILLER4683, 3.5 parts of DOWELLER WAX5050, 0.7 parts of amine neutralizer, 1.6 parts of thickener, 0.15 parts of light stabilizer and 23.55 parts of water.

3. The white skin composite resin composition according to claim 1 or 2, characterized in that: The amine neutralizer is an organic amino compound, selected from one or both of AMP-95 and DMAE.

4. The white skin composite resin composition according to claim 1 or 2, characterized in that: The thickener is a water-based thickener, selected from one or both of ACRYSOL ASE-60 and ACRYSOL TT-935.

5. The white skin composite resin composition according to claim 1 or 2, characterized in that: The light stabilizer is an ultraviolet light absorber or a hindered amine light stabilizer, and is selected from one or a combination of two or more of Tinuvin 123DW, Tinuvin 9945DW, Tinuvin 479DW, Tinuvin 783FDL, and Tinuvin 791FB.

6. The method for preparing the white skin composite resin composition according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: (1) Under stirring conditions, DOWELLIU RU2301, DOWELLIU RU2307, DOWELLIC RA1300, DOWELLIC RA1107, DOWELLIU PU20205, DOWELLER FILLER 4683, DOWELLER WAX 5050, a light stabilizer and water are mixed to obtain a premix phase; (2) After the premixed phase is uniformly defoamed, a thickener and an amine neutralizer are added and stirred. After completion, the mixture is filtered and packaged.

7. The method for preparing the white skin composite resin composition according to claim 6, characterized in that: In step (1), the stirring speed is 200-300 r / min, and the stirring temperature is 5-35°C.

8. The method for preparing the white skin composite resin composition according to claim 6, characterized in that: In step (2), the stirring time is 1 to 2 hours. After the stirring is completed, wait until the viscosity of the system meets the requirements of a 4# Ford cup for 25 to 35 seconds, then filter through a 300-mesh filter for packaging.

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