JPS6356355B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to a fixing agent used for fixing a fabric to a printing table in the printing process of textile printing, particularly screen printing. Conventionally, the following adhesives have been used: Aqueous solutions of water-soluble polymer substances such as starch paste, carboxymethyl cellulose, polyvinyl alcohol, and polyacrylamide; Heat-sealing substances such as paraffin, wax, and rosin; Vinyl acetate resins, ethylene-vinyl acetate copolymers, and acrylic resins. Emulsions or latexes of thermoplastic resins such as rubber-based, acrylic-based, silicone, etc. pressure-sensitive adhesives Adhesive tapes coated with the above-mentioned pressure-sensitive adhesives However, each of these adhesives has drawbacks. In other words, in the case of hydrophilic natural fibers such as silk and cotton, after printing, the fabric is re-moistened with water from the printing paste, and the fabric rises from the printing table due to shrinkage due to drying of the printing paste, resulting in multicolored The design of the stamp is misaligned. In addition, in the case of hydrophobic synthetic fibers such as polyamide and polyester, the water in the printing paste is not absorbed by the fibers but spreads to the back side of the fabric, impeding the adhesion of the adhesive. Not only will the print stand out even more (floating), but the color will also come out during the next printing (remaining color). In addition, washing after each printing process,
It is troublesome because it requires repeated reapplication.
In addition to having weak adhesive strength, paraffin and other substances adhere to the fabric in the areas pressed by the screen during screen printing and melt during heat treatment after printing. The adhesiveness varies depending on the affinity between the resin used and the fabric or printing paste, but if the adhesiveness is too strong, the resin used as a adhesive will transfer to the fabric (resin comes off) and when the fabric is peeled off, Since the printing paste transfers to the adhesive (residual adhesive) and contaminates the adhesive, it is necessary to reapply the adhesive each time.
It is necessary to wash the surface of the adhesive with water, and if the adhesive strength is weak, the fabric will shift during printing, resulting in poor mold fit. cannot provide sufficient tension to the fabric. For these reasons, it is most preferable to use pressure-sensitive adhesives as adhesives, but even if such adhesives are used, for example, in the case of rubber-based or acrylic-based pressure-sensitive adhesives, the following There are drawbacks such as. That is, when the fabric is peeled off after printing and drying, the printing paste is absorbed by the adhesive, causing uneven dyeing on the fabric surface. When the cloth is peeled off after printing and drying, due to the destruction phenomenon between the layers of printing paste, colored paste powder is generated, causing color scattering. Because the base agent becomes contaminated with colored paste, the color transfers when printing is performed next time. If the adhesive strength of the adhesive to the fabric is too strong, pattern deviations within the thread will occur due to twisting of the thread, while if it is too weak, problems such as lifting and shrinkage will occur. When using a silicone-based pressure sensitive adhesive as described in JP-A-54-30989, the above-mentioned
However, with repeated use, both the adhesive strength and releasability decrease, making it impossible to straighten the fabric (grain correction), and it is often necessary to apply a top coat of adhesive during use. This needs to be supplemented. The inventors of the present invention have carried out research aimed at resolving the drawbacks of conventional adhesives, and have found that they have a good balance between adhesion and removability after printing, and are effective at reducing uneven dyeing.
It is free from defects such as color scattering, pattern deviation, lifting, and shrinkage, and has suitable hardness and is non-contaminating. It is heated by heating from the back of the printing stand, and by blowing hot air. The present invention was accomplished by discovering a adhesive that can be used in any of the top heating methods and whose surface is not affected by printing pastes or special dyes. That is, the present invention provides (1)(A) R ¹ ₃ SiO _1/2 units per mole of SiO ₂ units (wherein R ¹ is the same or different substituted or unsubstituted monovalent hydrocarbon) (indicates the group) 0.4
In a proportion of ~1.0 mol, substantially SiO ₂ units and R ¹ ₃
30 to 80% by weight of a benzene-soluble polyorganosiloxane resin consisting of SiO _1/2 units and having 0.0004 to 1 reactive group bonded to silicon atoms per silicon atom; (B) a viscosity of 10000 to 200 million cP at 25°C; Silanol-terminated polydiorganosiloxane with 20
100 parts by weight of the condensation reaction product with ~70% by weight, (2) Substantially the general formula R ² ₃ SiO [R ³ ₂ SiO] _o SiR ² ₃ (wherein R ² and R ³ are an alkyl group and Mutually identical or different monovalent hydrocarbon groups selected from the group consisting of phenyl groups, n is 10 to 1000
Indicates the number of R ² and R ³ in the molecule,
20 to 100 parts by weight of a chain polydiorganosiloxane (of which 50 mol% or more is a methyl group); (3) an alkoxysilane having an amino group bonded to a silicon atom via a carbon atom; a partial condensate thereof; 1. A adhesive comprising: 1 to 10 parts by weight of a curing agent selected from the group consisting of metal fatty acid salts and dialkyltin compounds; and (4) 50 to 2,000 parts by weight of an organic solvent. (1) used in the present invention is a co-condensation product of the benzene-soluble polyorganosiloxane resin (A) and the silanol-terminated polydiorganosiloxane (B). The blending ratio of both is in the range of 30 to 80% by weight of (A) based on the total amount of (A) and (B). This is because if (A) is too small, good adhesion cannot be obtained, and if it is too large, the cured film becomes too hard and the adhesion is reduced. The benzene-soluble polyorganosiloxane resin (A) is composed of SiO ₂ units and R ¹ ₃ SiO _1/2 units (where R ¹ is as described above) and has a relatively low molecular weight. R ¹ is a methyl group,
Alkyl groups such as ethyl group, propyl group, butyl group, amyl group, hexyl group, octyl group, decyl group, alkenyl groups such as vinyl group, aralkyl groups such as β-phenylethyl group, aryl groups such as phenyl group, and Examples include those in which some of the hydrogen atoms of are substituted with chlorine atoms, fluorine atoms, nitrile groups, etc., but they are easily synthesized, have good weather resistance, and are highly reactive with (B). Therefore, it is preferable that 90 mol% or more of R ¹ is a methyl group, and (3) makes it easy to form a adhesive layer with appropriate adhesiveness and releasability at around room temperature. It is particularly preferred that all of ₁ are methyl groups. The amount of R ¹ ₃ SiO _1/2 units is between 0.4 and 1.0 mol per 1 mol of SiO ₂ units, and if the amount of R ¹ ₃ SiO _1/2 units is small, it is difficult to stably obtain benzene-soluble low molecular weight products. It tends to gel during synthesis or storage to become an insoluble and infusible polymer. Moreover, if there are many R ¹ ₃ SiO _1/2 units, the reactivity during condensation with the silanol-terminated polydiorganosiloxane (B) will decrease. Examples of the reactive group bonded to a silicon atom include a hydroxyl group, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a methoxyethoxy group, and an ethoxyethoxy group. Such polysiloxane resins are made by combining a tetrafunctional silicon-containing compound selected from alkyl silicates such as ethyl silicate and propyl silicate, partial condensates thereof, silicon tetrachloride, and water glass, and adding trimethylchlorosilane in the presence of a solvent. ,
It can be obtained by cohydrolyzing with a triorganochlorosilane such as dimethylvinylchlorosilane or dimethylphenylchlorosilane and removing by-products by conventional means. As a solvent,
Benzene, toluene, xylene, gasoline, n-
Hydrocarbons such as hexane and n-heptane are commonly used. As the silanol-terminated polydiorganosiloxane (B), one having a substantially linear siloxane skeleton and a viscosity of 10,000 to 2,000,000 cP at 25°C is used. If the viscosity is less than 10,000 cP, the resulting film will have poor toughness and flexibility, and if it exceeds 2,000,000 cP, the viscosity of the composition will increase, impeding workability. The organic group bonded to the silicon atom is exemplified by the same one as R ¹ in (A), and the balance between viscosity and necessary physical properties, reactivity in condensation with polysiloxane (A), and Although it is preferable that all of them are methyl groups because they are easily obtained and relatively easy to synthesize, an appropriate amount of phenyl groups may be introduced depending on the use and required properties. The co-condensation of the polysiloxane resin (A) and the silanol-terminated polydiorganosiloxane (B) is carried out by mixing the two and heating preferably in the presence of caustic potash or caustic soda. . The polysiloxane resin (A) usually has a solid content of 30
It is obtained as a ~60% by weight hydrocarbon solution, but if necessary, an organic solvent is added, then the silanol-terminated polydiorganosiloxane (B) is added, and the mixed system is heated. The organic solvent used is preferably a hydrocarbon solvent, with toluene or xylene being particularly preferred. The heating temperature is preferably between 80 and 150°C, and it is particularly advantageous to use the reflux temperature of the added solvent in terms of temperature control. It is preferable not to allow this condensation reaction to continue until completion, but to stop it when components (A) and (B) form a homogeneous phase and become a transparent solution. The polydiorganosiloxane (2) used in the present invention not only imparts appropriate releasability to the adhesive, but also imparts tackiness when (1) is relatively hard and lacks tackiness. It is a stable polysiloxane that is liquid at room temperature and has a chain-like siloxane skeleton. R ² and R ³ are methyl group, ethyl group,
Propyl group, butyl group, amyl group, hexyl group,
Examples include alkyl groups such as octyl groups and decyl groups, and phenyl groups, but in order to obtain good releasability, 50 mol% or more of the total must be methyl groups, which is easy to synthesize and removable. From the viewpoint of excellent properties and compatibility with (1), it is preferable that all groups are methyl groups. n is between 10 and 1000, preferably between 10 and 100. If n is less than 10, the vapor pressure will be high and it will evaporate during repeated use using the subthermal method, which is exposed to relatively high temperatures, resulting in decreased peelability. If n exceeds 1000, the viscosity will increase and it will be difficult to handle. It is inconvenient. The amount of polydiorganosiloxane in (2) is
20 to 100 parts by weight, preferably 30 parts by weight per 100 parts by weight
In the range of ~60 parts by weight. If the amount of (2) is less than 20 parts by weight, the peelability will be poor, and if it exceeds 100 parts by weight, the adhesive will become soft and stringy. The curing agent (3) can be heated at room temperature or relatively low temperature, for example 30 to 60℃, which is the temperature of the surface of the printing table.
(1) is a curing agent that forms a adhesive layer that remains sticky and is easy to peel off from the fabric after printing.It is an alkoxy group having an amino group that is bonded to a silicon atom through a carbon atom. Silane, a partial condensate thereof, a metal fatty acid salt, or a dialkyltin compound is used, but in order to form the above-mentioned adhesive layer at a relatively low temperature and in a short time, it is recommended to use it in combination with and/or. preferable. Examples include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-[β-(N-aminoethyl)amino]propyltrimethoxysilane, γ-[β-
(N-aminoethyl)amino]propyltriethoxysilane, γ-(methylamino)propyltrimethoxysilane, γ-(methylamino)propyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, δ-aminobutyltrimethoxysilane Although γ-aminopropyltriethoxysilane is the most commonly used because it is easily available, easy to handle, and highly effective as a curing agent, it is used alone or in combination with other curing agents. used in Examples include siloxane compounds obtained by partially hydrolyzing and condensing the alkoxy groups of the silane compounds exemplified above. Examples include tin octoate, tin laurate, tin naphthenate, iron octoate, iron naphthenate, lead octoate, lead naphthenate, cobalt octoate, cobalt naphthenate, dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, Dioctyltin dioctoate is an example, but tin fatty acid salts are preferable because they have high efficacy as a curing agent, do not interact with dyes, and do not cause coloring or discoloration even if transferred to fabrics. preferable. Examples include dialkyltin fatty acid salts included in , as well as dibutyltin oxide. The amount of curing agent (3) varies depending on its type, but for example, when a tin fatty acid salt is used in combination with and/or, (1)
A range of 1 to 10 parts by weight per 100 parts by weight is suitable. If it is less than 1 part by weight, the adhesive layer will be too soft and will not exhibit sufficient releasability, and if it exceeds 10 parts by weight, the effect of adding it will not be expected and the stability will decrease.
This is because a gel-like substance is produced. The organic solvent used in the present invention is to dissolve (1) to (3) to make it easier to apply, and includes benzene,
Hydrocarbons such as toluene, xylene, n-hexane, n-heptane, cyclohexane, gasoline,
Examples include halogenated hydrocarbons such as carbon tetrachloride and trichloroethylene. Among these, toluene and xylene are preferred because of their appropriate volatility, solubility of (1) and (2), and ease of handling. The amount of organic solvent in (4) is 50 parts by weight per 100 parts by weight of (1).
-2000 parts by weight, preferably 100-500 parts by weight. If it is less than 50 parts by weight, the viscosity of the system will increase, making it difficult to apply, and storage stability will deteriorate. If it exceeds 2000 parts by weight, a film of sufficient thickness cannot be obtained and is economically disadvantageous. The adhesive of the present invention may optionally contain resins such as silicone resins containing trifunctional polyorganosiloxane as a main component, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, and ethylene-vinyl acetate copolymers. They may coexist. Further, fine inorganic powders such as silica, talc, and calcium carbonate, cyclic polydimethylsiloxane, and liquid paraffin may be added. The adhesive of the present invention has excellent adhesion and peelability after printing, has a good balance between the two, and is free from defects such as uneven dyeing, color scattering, drawing up, pattern shift, lifting, and shrinkage. According to the present invention, a useful grounding agent suitable for textile printing was obtained. Hereinafter, the present invention will be explained with reference to Examples. In the following Examples and Comparative Examples, all parts represent parts by weight. Example 1 Consisting of SiO ₂ units and (CH ₃ ) ₃ SiO _1/2 units, the ratio of (CH ₃ ) ₃ SiO _1/2 units to 1 mol of SiO ₂ units is 0.65 mol, and the hydroxyl group to be bonded to the silicon atom is To 150 parts of a 50% xylene solution of polyorganosiloxane resin, add 25 parts of silanol-terminated polydimethylsiloxane with a viscosity of 7,000,000 cP at 25°C, dissolve uniformly, then add 0.02 part of a 10% aqueous solution of caustic soda, and stir. The mixture was then heated to the reflux temperature of xylene for 3 hours to advance condensation. Then
Cool to 35℃ and neutralize with 10% phosphoric acid aqueous solution.
After evaporation, xylene was added to prepare a 50% xylene solution S-1 of the polysiloxane condensation reaction product. To this, the above-mentioned S
-1, trimethylsiloxy-terminated linear polydimethylsiloxane F-1 with a viscosity of 50 cP at 25°C,
Inventive Samples 11-13 and Comparative Samples 14-18 were prepared by blending γ-aminopropyltriethoxysilane, tin octoate, liquid paraffin, and toluene. Using these samples as a base agent, a polyester fiber cloth was pasted on an iron printing table whose surface had been treated with urethane resin, and printing was performed using the over glue and anti-discharge dyeing paste shown below. The characteristics were investigated.

【table】

[Table] In other words, apply a sample of 80 to 90 g/m ² on a printing table, dry it, and paste it with a polyester fiber cloth.
Printing was carried out at approximately 30°C using the top heating method (heating with warm air). Printing was also carried out at approximately 50°C using a different heating method (heating was done by placing a heater under the printing table).
The hardness of the cured base agent layer, the adhesive strength and peelability after printing at the initial stage and after 80 repeated uses, and other findings when printing was performed using the top heat method and the bottom heat method, respectively. Shown in Table 2. Then, the fabric is pasted on a printing stand on which a layer of adhesive has been formed, and the printing is done once with the anti-discharge agent and once with the overglue, until the printed fabric is peeled off. A series of steps can be counted as one time.

[Table] Example 2 Samples 21 to 27 having the compounding ratios shown in Table 3 were prepared by changing the curing agent and adding cyclic polydimethylsiloxane and finely powdered silica. Experiments were conducted on these samples under the same conditions as in Example 1. The results are shown in Table 4.

【table】

【table】

[Table] (Note) *1 to *5: Same examples as in Table 2 3 Using the same method as S-1 shown in Example 1, various polysiloxane condensation reactions were produced as shown in Table 5. Material solutions S-2 to S-6 were obtained. Using these polysiloxane condensation reaction products, samples 31 to 36 having the compounding ratios shown in Table 6 were prepared. Using the sample thus obtained, printing was carried out under the same conditions as in Example 1. The results were as shown in Table 7.

【table】

[Table] Exists as a unit

【table】

【table】

[Table] (Note) *1 to *6: Same as Table 2

Claims (1)

[Claims] 1 (1) (A) R ¹ ₃ SiO _1/2 units per mole of SiO ₂ units (wherein R ¹ is the same or different substituted or unsubstituted monovalent carbonized (indicates hydrogen group)
In a proportion of 0.4 to 1.0 mol, substantially SiO ₂ units and
30 to 80% by weight of a benzene-soluble polyorganosiloxane resin consisting of R ¹ ₃ SiO _1/2 units and having 0.0004 to 1 reactive group bonded to silicon atoms per silicon atom; (B) 10000 to 20000000 cP at 25°C; Silanol-terminated polydiorganosiloxane with a viscosity of 20
100 parts by weight of a condensation reaction product with ~70% by weight, (2) substantially of the general formula R ² ₃ SiO [R ³ ₂ SiO] _o SiR ² ₃ (wherein R ² and R ³ are an alkyl group and mutually identical or different monovalent hydrocarbon groups selected from the group consisting of phenyl groups, n is 10
~1000, and 50 mol% or more of the total of R ² and R ³ in the molecule is a methyl group) 20 to 100
(3) 1 to 10 parts by weight of a curing agent selected from the group consisting of alkoxysilanes having an amino group bonded to silicon atoms via carbon atoms, partial condensates thereof, metal fatty acid salts, and dialkyltin compounds; , and (4) a adhesive comprising 50 to 2000 parts by weight of an organic solvent. 2. Claim 1, in which R ¹ is a methyl group
Adhesive agent as described in section. 3. The adhesive according to claim 1, wherein the reactive group bonded to the silicon atom in (A) is a hydroxyl group. 4. The adhesive according to claim 1, wherein the organic group bonded to the silicon atom in (B) is a monovalent hydrocarbon group selected from the group consisting of a methyl group and a phenyl group. 5. The adhesive according to claim 4, wherein the organic group bonded to the silicon atom in (B) is a methyl group. 6. The adhesive according to claim 1, wherein the polydiorganosiloxane (2) is 30 to 60 parts by weight. Claim 1, wherein the curing agent in (7) (3) is a combination of an alkoxysilane and/or a partial condensate thereof having an amino group bonded to a silicon atom via a carbon atom, and a metal fatty acid salt. The adhesive listed. 8. The adhesive according to claim 7, wherein the metal fatty acid salt is a tin fatty acid salt. 9 At least one component of the curing agent in (3) is γ-
The adhesive according to claim 1, which is aminopropyltriethoxysilane. 10. The adhesive according to claim 1, wherein the amount of curing agent (3) is 1 to 10 parts by weight.